Scribble-Bots – STE(A)M Project for Kids

A scribble bot is basically an out-of-balance motor attached to some drawing utensil. As the motor rotates, it vibrates, causing the drawing utensil to jiggle across the paper, making scribble marks. There are a lot of ways you could build one. Here’s a tutorial on the method we used with our class of 3 – 7 year olds with parent helpers. (Click on any picture for a bigger image.)

  • Turn a plastic cup upside down.Tape three colored markers to the outside of the cup, making a stable tripod. Align the markers so that the lids are just below the rim of the cup, and make sure the legs are an equal length.
    • Options: you could use popsicle sticks or other sticks for two of the legs, and only have one marker. You could use colored pencils or crayons, but they just don’t draw very well – the plastic cup is not heavy enough to put on enough weight to get a good mark out of these things that require some pressure to draw. Washable markers are your best bet. (We got permanent markers, because that’s all they had at the dollar store, and we had to buy 60 markers for our class so we needed them to be cheap. But, we came to regret the permanent marker choice….. tip: Purell or rubbing alcohol or alcohol wipes are great at getting permanent marker off tables, floors, and hands… not so good at getting it off clothes…)
  • Tape the battery pack on top. (Note, for most of this project, you can use masking tape, duct tape, scotch tape, glue gun – whatever you have. But if the tape might come in contact with electrical wires carrying current, use electrical tape there.)
  • Tape the motor on top so that the shaft on the motor is hanging off the edge of the cup.
  • Un-balance the motor. (This is necessary – if the motor is balanced and spins smoothly, the bot won’t wiggle around – it’ll just sit in place.) We used corks… use an icepick, nail, or something the right diameter to poke a hole into the cork about 1/3 of the way from the end on one side, then put the cork on the shaft of the motor.
  • Test for freedom of rotation… spin the cork around a few times. Can it rotate cleanly without banging into anything or getting blocked? If so, you’re good to go. If not, you need to adjust your design. (This project is a STEM engineering challenge, and often needs several steps of test something, re-do, test again to get it right.)
  • Decorate the bot as desired, with googly eyes, pompoms, pipe cleaners, etc.
  • Put down a BIG piece of paper (we covered a table in butcher paper). Take the lids off the markers. Set the bot on the paper, then connect the wires on the motor to the battery to complete the circuit, and off your bot goes!
  • Some bots work perfectly right away. Some don’t. (Remember, this is a STEM engineering challenge – it’s OK if it doesn’t work perfectly the first time – we learn from our mistakes and re-build!)
    • If it tips over on its side, you may need to spread out the legs a little more evenly to make the most stable tripod possible.
    • If it just stays in place and doesn’t wiggle around the paper, it’s because it’s too balanced. Take the cork off and re-mount it.
    • If bits fall off or the wires become disconnected by the jiggling, re-engineer a solution for the problem.
  • Here are videos of bots in action:


Where do you get your motor?

Some sources recommend taking apart an electric toothbrush, or a small fan. I wanted a 1.5 – 3 V motor and a single AA battery pack. Here’s what I found:

  • You could order a wiggle-bot kit from TeacherGeek. I was impressed with the high quality of the kit components, and also all the great downloads TeacherGeek offers, such as this overview, which includes Science Standards addressed with this project.
  • Teacher Geek also sells a small motor with leads, mount, and battery pack, which is quite nice quality with easy to use clips, for $3.00 each.
  • I ordered most of our supplies from Amazon. (Affiliate links follow.). I really liked these Motors with Alligator Clips, which were $18.95 for ten. (And Sci Supply offered great customer service. I’d accidentally placed a duplicate order, and they called me to check how many motors I wanted.) I used these Batteries and these Battery packs which were fine (cost 64 cents each), but had wire leads you had to clip the motor to. I preferred the battery packs from Teacher Geek which are 60 cents each, and have metal terminals you can easily clip the alligator clips to.

One note for clarification: A scribble bot does not meet our definition of a true robot (which we said has three parts – sensors, processor and actuator) or this definition on Galileo: essential characteristics include sensing, movement, energy, and intelligence, or even the Merriam-Webster definition of a device that automatically performs complicated often repetitive tasks. It’s really just a motorized toy.

Additional resources on how to build a scribble-bot:

  • Scribble-bots video
  • Robots that Draw from art4edu. Clear directions, a nice set of questions on “can scribble bots make ‘art'”, photos, and video. They use a 4-battery pack – I found one battery was plenty of power for our motor.
  • Science Sparks’ How to Make a Scribble Bot. Instead of using a battery pack, they use a rubber band to hold the motor’s metal leads onto the battery, and a glue-gun gluestick instead of a cork to unbalance it. The body is a Pringle’s container… we prefer the plastic cups – having the edges that spread outward helps set your markers at an angle that makes for a very stable tripod.
  • Lemon Lime Adventures’ DIY Scribble Bot tutorial shows taping the markers to the inside of the cup – we found it was easier for kids to tape them to the outside, uses a clothespin instead of a cork to unbalance it, and tapes the leads to the battery pack (they turn the bot on and off by taking out a battery or putting it back in.
  • Red Ted Art’s Mini Robot is a wiggle-bot; it doesn’t scribble. It uses three toothhbrush heads for the legs, the motor is the body, and the battery is the head.

Build a Cardboard Finger

Today we were in the Tinker Tank area of Pacific Science Center in Seattle, and they had an engineering project where kids could build a finger joint.

Here’s a tutorial for the simplest possible method:

Cut a piece of cardboard. Make sure the corrugated ribs are going across the strip, not up and down the length of the strip. Fold the strip every inch or so.

Cut short segments of plastic straw. Tape them lengthwise, one per section of the cardboard.

Thread a string through all the the straw segments. Tape it down at one end, and leave a loose end hanging out the other end. Pull on the loose string to bend the “finger joints.” Optional – add a handle to make it easier to hold on and pull the string.


Variations: Put straw segments on the front AND back of the cardboard. Run string in a loop – tape on the back, then run it through all the straws on the back, over the end, then through all the straws on the front, and leave the string hanging on the front. This led to a better / tighter curl when the string was pulled. (See photo of curled finger at top of post.)

Pincer grasp: take a flat square of cardboard (whoever made this one reinforced it with a couple popsicle sticks to make sure it couldn’t fold.) Then add a couple “spacer” pieces of cardboard. Then tape on your “finger” with the straw side DOWN toward the other cardboard. (First picture.) When you pull the string, the finger curves up against the lower cardboard, forming sort of a pincer grasp. (Second picture.) It can pick up small objects like this red Lego piece.


This is a fun, easy, hands-on project for kids that we may use in either our “Skeletons” class or our “Robots” class. And it fits both our tinkering aesthetic and our pulling materials from the recycling bin approach.

When we got home, I searched for other examples of similar projects online.

Kiwi Crate has a Straw Fingers project, where they just use straws and string – they cut notches in the straws to allow them to bend. You can choose to make five and tape them to cardboard for a hand.

On Carolina, to model a human hand, they take the notched straw idea, but then tape them onto a hand-shaped piece of cardboard, then score the cardboard so it will fold everywhere there is a joint.

RIT has a full lesson plan on bio-engineering, which includes a how-to on how to make a finger with wood, rubber bands, tape, string, straws, and cardboard.

Science Buddies has a fully detailed tutorial on how to make a robot hand from straws. Their directions include an evaluation of ways to improve the process. They use straws, string, polymer clay and plastic rings. Each finger has three rings, one for each joint so you can bend the joins separately. On Prezi, there’s a vaguer description (with no pictures) of something that sounds like a similar process… might be some tip you could glean from there.

Weird Science Kids uses a hand-shaped cardboard, bendy straws and string, and “glues” the straws down to the cardboard with clear silicone caulk (like you use to seal seams in a shower.) It looks complicated to me… and takes a couple days as you have to wait for the caulk to dry / cure.

PBS Kids has a “design a robotic arm” challenge.

All these examples inspire a lot of ideas for projects we could do. If working with younger children (preschool age – 3 – 4 or so), I would likely have them build just a single finger, either using the PacSci method I describe, or the straw from Kiwi Crate. For early elementary school age children (age 5 – 8), I would teach them a simple method for building a finger, then encourage them to figure out how to build a hand. For older children, I’d just show them this post, and let them decide how they wanted to build a hand.

100 Snacks

Today was my son’s hundredth day of kindergarten, so the teacher had all sorts of celebrations planned. I helped with the snack counting project, which was a great hands-on math experience. Parents had been asked to donate items. The teacher set out bowls of ten different kinds of snack items (kix cereal, bunny crackers, chocolate chips, etc.)

Counting Ten Sets of Ten

First, the children had to stand in line. They each took turns taking 10 items from the first bowl and putting them in a cup, then ten from the second, and so on. As simple as this activity seems to an adult, the fact is that these kids could not have done this successfully 100 class-days ago.

In that time, they’ve learned the social skills needed to stand in line, wait their turn, and not crowd the other kids. They’ve learned enough impulse control that 18 of the kids managed to do this task without eating any of the items. (One child ate some… I told him not to eat more… he ate more…) Their small motor skills have grown to the point that doing the pincer grasp needed to pick up these small items came easy to almost all. The only challenge was the raisins, which like to stick to each other.

They’ve all learned the counting skills to consistently and reliably count out exactly ten items. And even if they had kids on both sides of them who were verbally counting to ten, they were able to stay focused on their own counting. Virtually no one under-counted. Only a few over-counted or accidentally took a few extras. One child I over-heard counting “9 – 10 – 11 – 12 – 13…. oops, that’s too many. I need to put back 1 – 2 – 3, right?” There is one child who is prone to rushing all of his work, and thus getting sloppy, and he did that here, not counting carefully. I pointed it out to him, but didn’t make a big deal of it, as I knew it would reveal itself to him in the next stage of the process.

Laying Items on a Counting Grid: 1 to 100

Once they had their cups, with ten each of ten snacks, we went back to our work table. They had sheets with 100 numbers on them. I told them that they should cover each number with one snack item – this is great reinforcement of one-to-one correspondence – a vital math concept most of them didn’t have 100 class-days ago.

Sorting and Pattern-Making

I suggested that they do a pattern – maybe all of the popcorn in one row, then marshmallows in the next, or whatever they wanted to do. Here’s the results for my first group of six kids:

One child intentionally placed them randomly, saying that he did
not want to do a pattern. He just took whatever was on the top of his cup first and placed it at the top of the chart. At the end, I pointed out to him what was interesting about his was that all the big items (popcorn, fruit snacks) are at the top of the chart, and all the little items settled to the bottom of the cup, so they ended up at the bottom of the chart.

One child placed them with a great deal of intention and thought. But if there was a pattern, I couldn’t discern it. I asked her what the pattern was – she just smiled a mischievous grin. One of the other children noticed that the bunnies were in an almost diagonal pattern, but then they decided it wasn’t a full pattern. I asked her why she arranged them that way, and she said it’s where they looked the best.

Three children built horizontal rows – putting ten items across the top row, then moving on to row two, and so on down.

One child started by placing one of each item across the bottom row of his chart, so that row had a representative of each food type, then building up the columns from there, till he had all the food sorted into columns. 

The Kix Challenge

One snack was plain Kix cereal, and one was Berry Berry Kix. This was tricky, because the plain Kix is plain beige. The Berry Kix are three colors, but one of them is a just slightly pinkish beige. It was easy for kids to mistake if for plain Kix. This required some extra attention to detail to sort out these two items.

Checking their Math and Problem-Solving

As each child finished their sorting, I would ask them to double-check: were all numbers covered? Did each number box have exactly one food item in it? We made minor adjustments as needed. We’d run out of Cheerios at the end, and the last child to go through the line was one Cheerio short, but luckily another child at the table discovered she’d accidentally taken 11 Cheerios, so she shared one.

One child had two open slots in her butterscotch chip row, so we re-counted them and saw that she had only taken 8 so she got two more from the bowl. One thought she had an extra piece of popcorn, but after discussion, we decided that a small piece had broken off of one of the larger pieces of popcorn. Multiple kids had a few extra raisins (some had stuck together). One decided to add an extra 101 box to his chart for that extra raisin.

I asked all the kids: If you have ten sets of ten snacks, how many snacks do you have? They all really grasped today that 10 sets of 10 equals 100.


Once the snacks were all sorted, it was time for the reward: eating all the snacks! (Those they didn’t eat now were bagged up for later.)


We had 20 minutes for each small group to do this. It wasn’t quite enough. In each group, a couple of the kids were able to complete their chart and eat some snack, a couple kids were mostly done with the chart, and one child was nowhere near done. We had one child (my child, of course) melt-down when this happened. He really wanted to finish his chart and had a really hard time recovering from needing to stop part way through his time.


This was such a great milestone project – they were really able to use a lot of the skills they had developed over the past 100 days and be successful at this new challenge, which reinforced lots of key math ideas, and was a fun memorable way to celebrate day 100. There’s a lot of ways you could adapt this idea for multiplication themed activities. For example, if you were working on multiplying by 7, you could start with seven sets of 7. Then they eat one type of food. Then do six sets of 7. And so on…

If you like this post about observing kids’ learning process with math, check out the blog Talking Math with Your Kids.

Books about Simple Machines

img_20151013_163855105This post focuses on book recommendations. To see lesson plans for hands-on activities and demonstrations for each individual machine, click here: Inclined Planes, Pulleys, Wedges, Levers, Screws, Wheels & Axles. Here’s an Overview of Simple Machines.

Overviews. There are several books that give an overview of all the simple machines.

  • How Do You Lift a Lion? by Wells is my favorite book. It poses fun questions with silly illustrations, then does a nice job of describing the basic concepts of how the machines work. Covers levers (for lifting lions), wheels and axles (for pulling pandas on pallets) and pulleys (to deliver a big basket of bananas to a baboon birthday). You could read it all at once, or divide it up into three parts and read at different times as you cover each machine. Good circle time read. The vocabulary is a little high level, but the pictures are clear illustrations, so our 5 – 7 year olds were able to follow the science of it. Our 3 – 4 year olds didn’t get the science, but they liked the book anyway.
  • Move It! Work It! from the Science Songs series, sets a song about simple machines to the tune of Kookaburra. (Hear it: There are also additional facts about each machine on each page. The song is not a great work of art, but if you wanted to include a song in the unit, it does a decent job of capturing the ideas about simple machines.
  • Simple Machines by Allan Fowler is a good overview, with nice basic descriptions and examples, and it’s an appropriate length for circle time. Not as fun as Lion…
  • Simple Machines: Wheels, Levers and Pulleys by Adler is for ages 5 – 7. Nice illustrations, good examples of simple machines in everyday life, and good explanations. But too high level for our class.
  • Lever, Screw, and Inclined Plane by Thompson. Good descriptions, great pictures from National Geographic. But… it’s for ages 6 – 9, and too high level/too long for us to read in class. It could be helpful for an adult to skim through before class – I find it’s helpful if you have fresh in your head information that’s just a little more advanced / detailed than you might cover with your students – it helps you answer questions that may come up.
  • Smash!: Wile E. Coyote Experiments with Simple Machines is NOT a circle time read. It’s aimed at 8 to 12-year-olds, and would be over the head of most 3 to 7-year-olds in my class. On the other hand, the Wile E. Coyote character is appealing enough that my almost-5-year-old (who is a strong reader and has read LOTS of books on simple machines) really enjoys this book even if he doesn’t fully grasp it and enjoys then watching Roadrunner cartoons and talking about the science in them.
  • Simple Machines by Deborah Hodge. Photos and descriptions of lots of easy activities related to simple machines. Nice little descriptions of the science behind each one. Good source of ideas for teachers/parents, but not something I’d read in class, or put on the shelf, just because I find that if I put out books of activity ideas, the kids want to try them all right now.

Series Books about Simple Machines

There are several series which include 6 books each, one for each machine. I will summarize my impressions of the series, based on the books I read (I have read one or more from each series, but not all 6 of any series.) Here are the four criteria I ranked them on:

  • Pictures: Are they good photos (current, focused, visually appealing) of things that are interesting to kids?
  • Words: Would this be a good read-aloud book for a group of 3 – 6 year olds? Easy to understand and interesting to listen to?
  • Big Idea: Does it get, and adequately convey the key concepts about this simple machine and how it works? (For my summary of what I think those key concepts are, see my posts on each of the types of Simple Machines – linked at top of post.)
  • Examples: Are there several good examples of the machine that would be interesting to children? (But I don’t want examples of every single way this simple machine can be applied, because too many diverse examples could make it hard for a young child to remember the big picture.)

I honestly haven’t found any one series that I think is the absolute best, so I get some books from each of the series to share with my class. If I didn’t have access to a fabulous library system and had to buy just one series of books, I might choose the How Toys Work by Smith or the “Vs.” series by Schuh for my class of 3 – 6 year olds. This list is in approximate order of age appropriateness, so if you’re teaching elementary school, start at the bottom.

  • First Step Non-Fiction: Simple Machines to the Rescue by Schuh. (OK, it’s really confusing that this series is titled Simple Machines to the Rescue, just like the series by Dahl. I call this the “Vs.” series.) Titles include Making a Salad: Wedge vs. Inclined Plane and Hauling a Pumpkin: Wheels and Axles vs. Lever, Raising a Bag of Toys: Pulley vs. Inclined Plane and three others. For ages 4 – 7. They present a challenge kids can relate to that could be solved with a simple machine. Two people who are working together suggest two different machines. We learn about each, and they try using each. Sometimes one is better than the other, but often we see the benefits of using both. They do a good basic job of describing each machine and giving examples beyond what is covered in the story. What I like: engaging photos, engaging story line of finding a problem and working together using tools to solve it. Because we are a parent-child class, I especially like that some of the books are about parents and kids working together, and that often the kid has a great idea the parent hadn’t thought of. Although I love this concept of comparing and contrasting two machines, I think it would be helpful for kids to also read books that focus on just a single machine in detail. Note: this book series has a companion teaching guide, which is aligned with Next Generation Science and Common Core state standards, and offers a lesson plan and hands-on activities for each of the simple machines. You can download the teaching guide at
  • How Toys Work by Smith. 4 – 6 years. Titles: Ramps and Wedges, Pulleys, Levers, Screws, Nuts and Bolts, Wheels and Axles. Nice series – shows photos of toys, talks about the “tool” that is the theme of the book – how it works, what it does, and gives more examples of toys that use it. Very age appropriate non-fiction with a playful / colorful look. In some books (Pulley and Screws) the big idea is explained well. But others (Ramps, Wheels) will not give a solid understanding of the concept of the simple machine. I would use these books to engage my younger students, but also share some of the other series with my older students to better explain the concepts.
  • Blastoff Readers: Simple Machines. Author: Manolis. Books: Ramps; Levers; Pulleys; Screws; Wedges; Wheels and Axles. These would be my top choice if I had only 5 – 7 year olds, but they’re a little long and too sophisticated for my little ones. Bright colors and engaging pictures. Good diagrams and descriptions of key concepts – very clear. Nice examples.
  • Useful Machines by Oxlade.  Books: Ramps and Wedges; Levers; Pulleys; Screws*; Wheels.  Review: Good pictures, engaging and easy to understand for 5 – 7 year olds. I have only read the screw book, but I like it a lot. However, I would not use it as the intro to screws. Once kids had a solid grasp of the basics of screws, it does a nice job of giving examples of all the different applications
  • Simple Machines by Bodden. Age 5 – 7. Books: Inclined Planes, Pulleys, Levers, Wedges, Screws, Wheels & Axles. Explains the machine, talks about how it makes work easier, shows a little history and modern examples of its use. It’s OK for this age group… a little dry and the graphic design is kind of stodgy looking. (Really lovely from an adult perspective… just not very kid appealing.) In general concepts are very clear and easy to understand and examples clearly illustrate the ideas. But, I thought the screw book was unclear and jumbled examples together that it wasn’t clear how they related. We used several of these books in our circle times in class, but tried to balance with How Toys Work, which are brighter and more fun.
  • Simple Machines by Tieck. Age 6 – 9. Inclined Planes, Pulleys, Levers, Wedges, Screws, Wheels & Axles. Perfectly fine information, good illustrations. Multiple examples of each machine. No activity ideas. Probably the best descriptions of the big idea, but presented in a dry, bland non-fiction style. I didn’t read them in circle, but did have them on the bookshelf for kids who wanted to learn more.
  • Simple Machines by Armentrout  Age 7 – 9. Inclined Planes, Pulleys, Levers, Wedges, Screws, Wheels. Each book talks about simple machines in general and then one machine specifically. Uses photographs of kids using simple machines, which helps it be more accessible / engaging to kids. Photos with labels help to clearly illustrate the tool and the principle. Fine series. In a few books there were so many examples, the big picture could get lost.
  • Amazing Science: Simple Machines by Dahl and Shea. Books: Scoop, Seesaw, and Raise: A Book About Levers; Roll, Slope, and Slide (Inclined Planes); Scoop, Pull, Lift, and Lower (Pulleys); Cut, Chop, and Stop (Wedge); Tires, Spokes, and Sprockets. Book description says they are for 5 – 10 year olds. For 5 – 6 year olds, the illustrations are great and the examples are clear, but I would not read the word as written – I would just paraphrase. I think they’re best for 7 – 8 year olds, as the 9-10 year olds might find the illustrations a little “young.”  The pulley book and inclined book don’t do the best job of explaining key ideas.
  • Early Reader Science: Simple Machines by Dahl.  Books: Ramps and Wedges; Levers; Pulleys; Wheels and Axles.  Review: Pictures OK, but not especially appealing to young ones. Length-wise, it would be OK for circle, but vocabulary a little high level. The Wheels book gives examples of so many different kinds of wheels and axles (steering wheels, gears, sprockets, cranks, cams, etc.) that the basic concept is lost. Does not mention friction. [not available on Amazon, but you may find at library]
  • Simple Machines to the Rescue by Thales. 6 – 9. Inclined Planes to the Rescue, Levers ttR, Pulleys ttR, Screws ttR, Wedges ttR, Wheels and Axles ttR. Focuses on how we use simple machines to solve problems: “it’s snack time and two people want to share one apple. How can they split it into two equal piece? Wedge to the rescue!” Good descriptions, nice examples. Each book ends with a little sample project kids can do. I’m not a fan of the photos and illustrations, and don’t think kids will find them as engaging as pictures in other series. I just find that they do the weakest job of explaining simple machines concepts. For example, in the screw book, their first example is a lid on a soda bottle, then a spiral staircase, then Archimedes screw, then an olive oil press, and then it talks about things that are held together by screws. Nowhere in there does it really describe what a screw is and what type of work each of these tools has in common.
  • My World of Science by Randolph. Books: Inclined Planes in my World; Levers in…; Pulleys in…; Wedges in… ; Wheels and Axles in… [there doesn’t appear to be a Screws book] Pictures are fine; words are appropriate level and the book is a good length for circle time, big idea is explained well, and there are lots of examples, but they all tie together in a clear logical way to the same big idea. It ends with asking “can you think of [wedges] you see around you?” Then offers a picture glossary of key words. This is a reliable, useable, but not exciting series. Note: this series is bilingual English / Spanish. So Wedges in My World is also Cunas en mi mundo. Each page has the text in English first, then Spanish. Book descriptions say age 7 – 10

Contraptions – Engineering for Kids


Engineering: My co-teacher and I attended a workshop last year called “The E in STEM – Exploring Engineering in Early Childhood” done by the folks from Kodo toys ( They said Engineering is all about problem-solving – you find a problem, you work toward a solution. Play is when kids make up problems to solve and call that fun. The focus of play is on the process – once you’ve solved one problem, you set up a new, more complicated one to solve.

The final week in our Engineering unit at Family Inventor’s Lab was Contraptions and Rube Goldbergs: Designing Interactions between Simple Machines. It was all about taking tools and concepts from our simple machines unit and our engineering unit and combining them in fun and playful ways. This was a day about Tinkering where kids were encouraged to build something, test it, adjust it, test it again, say “hey I wonder what would happen if we added X”, add X and test it again.

Activities for Tinkering with Chain Reactions and Contraptions

Challenge of the Day / The Launch Table: On one table, we set up a target to aim for, pompoms for ammunition, and then ramps, levers and fulcrums, corks, dowels, blocks and plastic spoons for launch equipment. (In past classes, we had explored Inclined Planes, Levers, and Catapults.) Kids were just shown the target and given a couple suggestions for what to try, and then left to play. I listened in on a couple of parents giving great guidance and asking great questions to extend their child’s learning. “What do you think will happen if…” “Hmm… that’s not heavy enough… can you find something heavier?” “OK, you got great height with that launch, but how can we work on accuracy – aiming it toward that target?” “If you roll this dowel down the ramp, would it hit the target?” “You’ve got great accuracy when you aim from up close  – what if we launch from further away?”


Ball Launcher: We brought our scarf cannon, but used it for launching balls (soft plastic balls like you would find in a ball pit, and Styrofoam balls.) Kids played “golf” with it, where the goal was to aim the tube so that when the ball shot out, it would roll through the tunnel blocks. They also did a variety of other experiments… a fun one would be to tie a hoop in the air and try to shoot the balls through it.


Ramps, Tunnels, and Balls: We have a Discovery Ramp kit from Kodo kids that allowed the kids to build some fun ramp projects.

Duplo Simple Machines kit: In the other weeks of our engineering unit, we would put out materials and instructions for a single project to do with Duplos. The goal those weeks was to give children practice following directions to achieve a pre-designed result. This week we put out the full Simple Machines kit for them to do free designing with.

DIY Marble Run: We had our ball wall there for kids to play with.


Marble Run: We also had this marble run, which is great, and could also be used as part of a larger Rube Goldberg series of actions, as seen in the video on this Tinkerlab page:


Train: We have a Domino Train which sets up perfect chains of dominos to knock over.

Domino Runs: We had dominos so children could set up chains of dominos to knock over. It’s fun to also include some “triggers” for Domino chains – things you can use to push over that first Domino in the chain. Examples we had were our Conveyor Belt from inclined planes week, our Wrecking Ball and pull-back car from Towers week, and a tube that you could aim at the dominoes then roll a marble through. It’s also fun to include some “goals”, such as a target to hit – we used a Duplo tower to hang a musical triangle in so the Domino chain could ring the bell at the end. This is a Rube built by one of the dads:


Pulleys: There’s all sorts of stuff you can do with pulleys and Rubes, but we just didn’t have enough time to use all our ideas. But, if you have a more extended time, be sure to include pulleys! (Read about our Simple Machines unit on pulleys.)

Crafts and Play

Button Spinners / Whirligigs: (Original idea from (Housing a Forest and Play, Eat, Grow)  Prep: These are traditionally done with large buttons. We wanted a bigger toy, so we used old CD’s – we glued a button in the center with Tacky Glue. You can also use any metal or plastic disc (baby food jar lids, margarine tub lids, or cardboard disks) and just drill two holes near the middle.

In class, kids decorate them with Sharpies, then ran a string through two holes. Kids could then put the fingers of one hand through one end of the string loop and the fingers of the other hand in the other end. They wind it up until the string is twisted tight, then stop twirling, hold the strings taut, and watch it spin. See a video tutorial at: and here’s more on how to spin it:


Depending on the materials used, whirligigs can make a buzzing sound when they spin, especially if the outside edge of the circle is cut in a sawtooth pattern. See an article on the history of these at

Researchers have now realized this simple technology can be used as a cheap, electricity-free centrifuge. By playing around with the disc size, hole positions, type of string and other variables, they have developed one that can spin at up to 125,000 revolutions per minute – the fastest rotational speed achieved by a human powered device. And fast enough to separate cells in blood samples for low cost diagnostic testing by health care workers in the lowest resource places in the world.

Craft: Climbing Critters: Make and Takes had a great post on how to make simple “climbing critters” – cardstock animals you mount on a loop of string – when you pull on the ends of the string, they “climb.” I made up a poster with instructions.

Mouse Trap: We set out the game Mouse Trap – a fun pre-made Rube Goldberg.

Water table: We put water wheels in the water table.


Intro to Concept: At opening circle, we talked about Rube Goldberg and showed one of his books of illustrations (Rube Goldberg: Inventions!), and we explained the idea of putting together a ridiculously complicated series of mechanical actions to accomplish a simple mechanical task. For example: instead of just turning on a light switch, you set up a ramp and a pulley, where you roll a ball down the ramp, it falls into a basket which pulls the pulley, which turns on the light. Why not just turn on the light switch? Because it’s more fun this way.

My co-teacher had built this sample Rube to demonstrate during circle. The design was based on this video:

IMG_20160312_140905800   IMG_20160312_140859020

Sometimes the demo works, and sometimes it doesn’t, and everyone laughs together, then we re-build it and try again. It’s a good way to talk about the fact that sometimes things don’t work right the first time – it doesn’t mean we’ve failed and it will never work. It just means it doesn’t work YET and we might need to work a little harder on it. (Last year, my parent education session this day was on “Willingness to Fail is the Key to Success” on the Growth Based mindset, intentionally matched up with the kids’ theme of the day.)

After circle, we let the kids play with the Rube, and there was another peg board and supplies next to it to encourage kids to build their own

Books: We read the book Lights Out, which tells of a piggy who needs to figure out how to turn off his lights from his bed after he falls asleep. It’s a wordless book that shows a VERY complex series of contraptions – fun to read if you add sound effects – “thwack” goes the broom on the seesaw; boingeduh-boingeduh-boing goes the ball down the stairs.

At closing circle, we read Mechanimals about a farmer who builds mechanical animals, including a pig that flies. Some books we’ve read for previous themes that could tie in to contraptions are: Awesome Dawson and Wendel’s Workshop from Robot week, Violet the Pilot  and Rosie Revere, Engineer from Wind week and The Most Magnificent Thing. You could also include Dumpster Diver – described in my list of books about Inventors. (These are all affiliate links for learning more – books can be purchased from Amazon, or you can get them from the library.) If you know of a great book about a kid building contraptions or Rube Goldbergs, tell me about it in the comments!

Song – we didn’t find a song we loved for this week – best idea was Button Factory, which turns the child into a “kinetic sculpture” of movement. (Find videos on YouTube if you don’t know the tune.)

Hey! My name is Joe. And I work in a button factory
One day my boss came up to me.
He said “Jo, are you busy?” I said,”No”
He said “push this button with your right hand”

Apps and Videos

A great preview for this class would be to go to and watch his video called Joseph on Sesame Street – about Kinetic Art. Then watch any of his other videos! Also, on YouTube, just do a search for “domino chain reactions” or “Rube Goldberg machines.”, and you’ll find PLENTY of videos to entertain you.

A fun way to prepare a child for this class or to review the ideas could be to explore a “contraptions” app. This is completely optional!!!! Parents who don’t like their child to do screen time, can feel free to skip this idea. My favorite is Inventioneers. Pettson’s Inventions, by the same company, is also quite good. Bad Piggies, from the Angry Birds Universe, also is a contraptions app. If your child ONLY does the app and only builds virtual contraptions, I think that there’s limited learning potential here. But, if they work with real, physical objects hands-on, then explore in an app, then return to the physical objects, I think it can be a nice tie-in.

Inventioneers: This app is available on Android and IOS. It is free in the Kindle app store. It’s all about Rube Goldberg type processes – you drop an apple on the character’s head, he turns on his blower, which turns a fan, which moves a gear, which knocks the basketball off the platform onto the seesaw and into the basket.

A 6 or 7 year old might be able to play it alone if an adult played the first few levels with them to give them the basic concept. A 4 or 5 year old can enjoy watching an adult play it. You usually don’t get the answer right on the first try – you set up part of the process, press play to test it, adjust it, test it again, set up the next part of the process, test that, adjust it, and so on. Talk it all through with the child. Tell them what you’re trying and why. Ask them why something didn’t work and what you can do differently. It’s definitely a learning process which requires lots of tinkering.

More Ideas

If you want to play more with this idea, it’s easy! Just put out loose parts, like blocks, bells, pulleys, dominoes, marbles and more. Give your child a challenge to complete. Encourage building a step at a time. For example, if the goal is to ring a bell, maybe they first build a domino chain to ring it. Then they add a wrecking ball to trigger the dominos. Then they add something to bump the wrecking ball to get it started and so on.

I’ve pinned several ideas here:

The best discussions on the topic are: Rube Goldberg machine on Tinkerlab, and Gadgets and Contraptions at Science World. Enjoy!

Someday, I’d love to try building some automata to share in class. Learn about Automata at Exploratorium.

Designing a Sailboat for a Preschool STEM Class


A few weeks ago, I wrote about the process I went through designing a car that kids age 3 to 7 could build in my Family Inventors’ class. Now, for our upcoming session on Wind and Flight, it was time to design a sailboat that they could build.

My criteria:

  • possible for kids as young as 3 to build
  • must be able to float in the water table, and survive getting wet
  • must have a sail that can catch the wind, so kids can use a straw to blow it around (the theme of the week is wind, after all)
  • materials must be affordable, easily accessible, and require a reasonable amount of prep time. Bonus points for re-used / recycled materials
  • if you were planning to have kids float their boats on a stream or lake, you should tie a string on so the boat can’t float away out of reach AND use biodegradable materials in case you lose the boat to the water

I searched the internet (especially Pinterest) for ideas.

Options for boat body

With each of these options, I’ve linked to a webpage that has photos of this kind of boat and info on how to build it.

  • Corks. You could use a single cork – it would be likely to tip over when you blow at the sail, unless you use a weight for a keel – this author appears to have attached pennies to the bottom. Or using two or more corks would increase stability. They can be attached together with rubber bands, hot glue gun, or waterproof tape. I wondered how I would get enough corks for my class, and discovered you can order 100 Recycled Wine Corks for $16
  • Ice Cubes – fun idea for summer, but not something kids can make in class
  • Milk carton with one side cut out. My concerns were: gathering enough cartons, time for cleaning and prepping them, avoiding milk allergens
  • Plastic – I have corrugated plastic from old election signs and such. We used it for our retractable cars. It’s waterproof, flat, with channels for air. I tested it, and it floats well.
  • Pool noodle – Can either do by slicing the noodle into 1-2 inch thick “donuts” or by cutting 5 inch segments and then slicing those in half lengthwise. Potential issues: can you buy pool noodles in November? Also, prep time.
  • Popsicle sticks. Need to have a waterproof glue to fasten them together. If you’re comfortable with your child using a glue gun, that would work fine.
  • Popsicle sticks and corks combined.
  • Sponge. On the upside, zero prep if you use a whole sponge per boat. Downside: cost
  • Styrofoam meat trays. Potential concerns: where would I get them (we don’t cook meat at home), and cleaning to avoid food-borne bacteria. Styrofoam bowls, like you might get ice cream in, are another option.
  • Miscellaneous recycled materials. A great tinkering exercise would be to just gather lots of random materials from the recycling bin: lids, plastic bowls, plastic bottles you can cut the top off of, cups, Styrofoam egg cartons, etc. You’d need to have a way for them to mount the mast for the sails without necessarily cutting a hole in the bottom of the body. Maybe silly putty or a clay that they could stick to body and plant mast in.

I tested the corrugated plastic – it works fine. Takes a little prep work to cut all the bodies, and cut slits in them for masts, but it would be a do-able project.

img_20161116_164733114 img_20161116_164835122

I ended up settling on corks. I haven’t used a glue gun in my class yet, and I know that taping round corks together would be a challenge for my students, so we’ll fasten them together with rubber bands. This also offers the advantage of being able to take them apart and re-use materials for other projects.

Options for mast:

  • Straws, popsicle sticks, dowels, and skewers – we have plenty of each. Because popsicle sticks are flat, they’re easier to fit between corks, so we’ll use those.

Options for sail:

  • Cardstock (works till it gets wet for the first time), craft foam, duct tape (see how to make a duct tape sail), sheets of flexible but strong plastic – I had one sheet of plastic, but have no idea where it came from. I have a laminator, so I tried printing pages with fun designs on them (pirate flags, Viking long boat design, etc) and sealing those in laminator plastic, then cutting out the flags. Sadly, after spending a little time in the water, the little bits of paper exposed at the cut edges would wick in water and the sealed paper would get wet. If I used the laminator in the future, I think I’d just seal close an empty sleeve – a little more flexible than ideal, but it’s an easy source for something workable.

Tutorial for Final Boat Design

Prep: Cut sails. I made 12 sails from a 8.5 x 11 sheet of plastic or of laminated paper. Cut slits big enough to slide popsicle stick through.


Assembly in class

  1. Mount sail on mast by sliding popsicle stick through the slots on the sail.
  2. Rubber band together two corks (cork A and cork B)*
  3. Rubber band together cork B and C.
  4. Put mast between cork B and C, facing toward A.
  5. Rubber band all three corks together.

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* Note: you could just rubber band all three together, but they may bunch up into a triangle if you do that.

littleBits vs. Snap Circuits

snap-circuits-vs-littlebitsThis post is a comparison of two modular electronics kits aimed at young children (through adults). We used both in the session of our Inventors’ Lab class where we talked about Electricity. (Note: I’ve also added some thoughts on Cubelets from Modular Robotics at the bottom of this post.)

Snap Circuits

What are they? Modular electronic components that snap together. You first lay out the configuration you want by snapping components onto a base plate which helps keep things evenly spaced. Then you connect them by snapping on wire modules to close the circuit. Here is a photo of a basic configuration with a switch and a light.


What are the components in the system?

They are plastic “building blocks” with metal snaps that click together. Blocks include:

  • Power source block for the batteries
  • Switch blocks – slide switch and press switch
  • Resistors
  • Lamp blocks, motors, music blocks, speakers
  • Wire blocks of different lengths, ranging from one snap to six. These are just used to connect other components to transport electricity. There are also jumper wires which allow more flexibility.

Circuits need to always include: a battery block, at least one component that limits the current through a circuit (such as the speaker, lamp, motor, or resistor.) If a child uses wire blocks to connect the two terminals of the battery, either directly with one block, or with a circuitous path of wire blocks only, it will cause a short circuit. Short circuits can damage components or drain your batteries.


Elenco, the company which makes Snap Circuits has been making kids’ electronics sets for many years – they were founded in 1972. They do many things very well. But, in attempting to be very scientifically accurate in their descriptions, they are too high level for the intended user (kids age 7 and up for this product). For example, “the photoresistor is a light-sensitive resistor, its value changes from nearly infinite in total darkness to about 1000 ohms when a bright light shines on it.”

Many of their details will be great someday when your kid is a 13 year old electronics geek who wants all the details. But, they’re mostly useless to a 7 year old who just wants to assemble circuits.


The assembly instructions for the projects are done as diagrams primarily, with some text next to them. Sometimes the text explains some info about the assembly, sometimes it talks about the science of what you’re doing, but it’s never step-by-step instructions. You rely on the diagrams for that. But unlike LEGO instructions, which break things down into several steps, these show the fully assembled circuit. The components are labeled with a 1 or 2 to show whether they’re in the first layer you lay down or the second (or third…)


For my almost 5 year old son, and for the 3 – 7 year olds in my class, these instructions are simply not comprehensible.

I wrote my own set of simplified instructions for the first several projects, which

1) change the objective to something easier to grasp and more appealing to a child (e.g. “to show how electricity is used to run a direct current (DC) motor” becomes “turn the switch on and the motor runs to turn the fan.”)

2) Add simple step-by-step instructions

3) instead of the multi-layer diagram, break it down into pictures which shows the first layer, then the first with the second added on, and so on.


Here are cards with simplified instructions for 6 simple circuits. You’re welcome to print and use them.

When we used Snap Circuits in class, we set the kit out with the cards describing 6 different projects and encouraged them to try building them. Some also experimented with their own designs. We did have to go over and disassemble and tidy up projects on a regular basis so that other kids could find the items they needed.


Age: Manufacturer rates as age 7 and up. In our class, we saw that for our 3 – 4 year olds, they liked watching their parents assemble it, but they really weren’t following the science of how the circuit works. And their fine motor skills and finger strength just weren’t up to the task of assembling circuits. Our 5 – 7 year olds fared better, but it was definitely a fine motor challenge. These older kids could follow the directions that I wrote (see above) but can’t follow the single-illustration instructions that appear in the book.

Where to Start: We’ve got the Snap Circuits Jr. Discovery Kit which has 30 parts, and instructions for 100 projects. It’s plenty to get you started.

Cost: The Jr. Discovery kit is only $17.50, so it’s easy to jump into this system. Their most expensive non-classroom-pack kit is the Snap Circuits Extreme SC-750 which is $71.

Expandability: There are many kits of Snap Circuits, with many components. There’s a lot you can do with them. The Snap Circuit Jr. kit has over 100 projects, including Lights & Police Sirens; Bomb Sounds, Alarm Circuit, Musical Doorbell, Spin Draw. Plenty of things to learn and discover. But, in the end, they’re limited to the Snap Circuits attached to the baseboard, and can’t offer the range of opportunities that littleBits offer.

Summary: If you’re looking for an affordable electronics kit for a geeky kid, age 7 – 12 who loves just sitting and building electronic circuits, this is a great product!


What are they? littleBits is kind of the Lego of electrical circuits. It’s a modular system.

The photo on the left shows a basic configuration: power cell, input switch (a push button) and an output (a bright LED light.) The photo on the right is a simple “project” hooking together the power and a motor. I built a little fan using a blue bead and some green plastic to mount on the motor. I set the motor on a wood block to give the fan room to turn.

IMG_20160111_194953046 img_20161104_122239419

What are the components in the system?

The pieces are color coded by type:

  • Blue for power – the power switch you attach to the battery or to a USB cable.
  • Pink for inputs / controls – Take inputs such as sound, light, or pressure to affect the flow of current. Button, dimmer switch/ volume control, sound activated switch, light sensor switch, remote controllable switch, oscillator, etc.
  • Green for outputs / actions – These modules do something. Lights, buzzers, motors, fans, speakers, etc.
  • Orange for wires – Include a simple wire that just lets you separate your bits by a few inches, and a splitter, where two inputs can connect to one output. Then all sorts of components from inverters to USB I/O to MIDI.

A slogan in the instruction book is “you always need a blue and green. Pink and orange are optional in between.”

The color coded blocks snap together with magnets. They only go together the “right” way. If you try any other direction, the magnets repel each other. This ensures that the circuit will work, and you can’t short circuit.

The order you assemble components in matters: the pink inputs only affect components that come after them in the circuit.

Instructions: The base kit comes with an instruction book to explain the basics, and some simple configurations of bits.

basic-littlebits  basic-projects

For our class of 3 – 7 year olds, I thought having many ideas all on one page might be confusing to them, so I made up a set of 8 cards with photo instructions for 8 simple configurations of bits. (Feel free to print and use: littlebits PDF.) We set out the cards with a couple trays that let us sort bits by type so the kids could collect what they needed to assemble each project. For the 3 – 4 year olds, I would sit with them and explain the basic ideas to them and explore with them. The 5 – 7 year olds could do this self-guided.

lightsensor img_20161105_092317555

The instruction book also contains “ideas to get you started” on projects – other things you can invent by combining your littleBits with a wide variety of materials. The goal is to encourage tinkering. One of the sample projects they offer is the Art Bot (see photo). My son’s favorite was a joy buzzer called the Prank Handshake, which involves fastening the battery pack to your arm, running a wire down to a button input in your hand, and then another wire up to the buzzer. You hold them all in place with a rubber band, then slide your sleeve down to cover the power and buzzer.


We’ve played with this expandability a little. For example, we took the simple set-up of power module, wire, and motor. But then we built a windmill with popsicle sticks. When you turn on the power, the propeller rotates.


Age: The manufacturer says they’re for ages 8 and up, but my five year old can do everything with them that was in the instruction book, and come up with some of his own ideas. Even the 3 year olds in my class could handle the basic concepts. I don’t think there is a maximum age. When I look at all the possible components and project ideas, I think this system could continue to intrigue and challenge people of all ages.

Where to start: We have the littleBits Electronics Base Kit. You could also consider littleBits Rule Your Room Kit – I can see it really appealing to an 8 –  9 year old.

Cost: Here’s the downside to littleBits. A basic kit costs $100. They go up in price from there. You can also buy individual components at the littleBits store, for anywhere from $5 to $50 depending on what you buy. When I put them out in class, I’m really crossing my fingers that none get lost or stepped on. I can’t attest much to durability – they seem pretty sturdy, but since my boy wore his joy buzzer around a lot, the button component has been flaky, and I think one of the wires was damaged. The light sensor has a small screw to adjust the sensitivity – the kit comes with a little plastic screwdriver, but it got dinged up in one or two uses, so we use a metal one, but I worry about stripping the head of the screw.

You could also build your own DIY littleBits if you’re confident with a soldering and working with wiring. Tutorials at:

Infinite Expandability: The cool thing about littleBits is how you can use them with a huge range of other materials to create all sorts of fun projects. Because you’re not soldering anything together, it’s easy to take apart, re-assemble, test, take it apart and assemble it differently until you get the result you want. I’ve barely begun to play with this expandability, so will just share here some other people’s ideas:

At, littleBits users share their ideas. Today’s page there includes:

  • Harry Potter inspired projects: an animatronic Hedwig (when a motion sensor is triggered, a servo moves the head and lights flash in the eyes), a Voldemort disarmer, a Parselbot (a wheeled cart that moves an egg-carton snake), and a motorized Lego Hogwarts Express you control with a smart phone
  • Halloween challenge winners: a remote control ghost, a haunted house diorama with spinning furniture and flashing lights, and a scary Zombie that can be activated from inside the house to scare off trick or treaters with flashing lights and a scream
  • LOTS more!

Boston Tech Mom collects links to 30 top rated littleBits projects for kids, such as an electric toothbrush, box monster, and bubble flute.

A post on lifehacker on how to get started DIY’ing anything with littleBits covers:

  • getting started with the cloudBit, which connects your littleBits project to the internet and to other devices, such as a smart phone
  • getting started with the Arduino module
  • sample projects: get an SMS notification from a doorbell, build a weather dashboard that pulls real-time data from Weather Underground, and make your own MIDI synth

This page on Instructables collects projects like: LEGO house with garage door openers and windmills, a motorized mobile, and a spinning, blinking paper Tardis

Science Education Note: These are not great for teaching the idea of a circuit to kids. If you take a battery, hook a wire from it to a lightbulb, then another wire from the lightbulb to the other terminal on the battery, kids totally see and understand the idea of a circuit. In the littleBits, the wiring is hidden from sight, so when a kid hooks a light to the power module, they can’t see how the electrical current is traveling from the battery through the light and back to the battery.

They also do not offer the technical details in the instruction book. An Amazon reviewer, Joel Avrunin, noted “I really do wish they would use the technical term instead of the popular one … The dimmer module is a potentiometer/variable resistor. The toy is so easy to use, why not let kids learn the right terms while they play? The light sensor is a nice little device (though they could have called it a photodetector or photodiode).”  I agree and disagree… I like the instructions as they are, for making the system seem easy and accessible to kids by not using those technical terms. But it would be nice if there was a supplementary manual for older kids with the “now that you’ve played with them, you want to know more about how they work” approach and all that vocabulary.

Summary: I have to say: I LOVE the littleBits. They’re a great toy that my five year old really enjoys and learns from, plus we can keep them around and re-introduce off and on as he gets older, continuing to take his inventing skills to a new level. And they’re cooler than the nerdy Snap Circuits. But… they’re stupidly expensive! I am hoping that over time, with economies of scale, (and likely competitors) the price comes down. But for now they’re quite pricey.

Cubelets by Modular Robotics

I learned about these when shopping for robots. I think they’re mis-marketing these by calling them robots, as they’re not what most people would think of in that category. But, they do look pretty cool as competitors for Snap Circuits and LitttleBits in the snap-together electronic components field. I have not tried these, so can only tell you what I’ve learned from reading about them on Amazon. 

What are they? Two-inch cubes that click together with magnets. One is a battery pack, and like littleBits, the current and the “programming” travels through to the others when they’re clicked together.

There’s a good introduction to this system on their website:

Components: Sense blocks which include a light sensor, distance sensor, a temperature sensor, and a knob. Action blocks include a flashlight, drive – a set of wheels, a bar graph of lights,  and a speaker. Think blocks include one that blocks signals going through, a Bluetooth for remote control, inverse, minimum, and maximum cubelets. There are also plates for connecting the blocks with Lego – one’s like the bottom of a Lego that you can mount on top of other Legos, and one is like a top, that other Legos can be built on top of.

Where to Start / Expandability: The Cubelets SIX robot blocks comes with a battery cube, Drive, Flashlight, Distance, Brightness, and Passive Cubelets. It’s $160. Other cubes can be bought in kits, or individually on their website, for around $27 a cube.

Age: They say 4 and up, and the reviews on Amazon confirm it works for kids as young as 3 and that 12 and 13 year olds also have fun with it. (Although they tire over time with the limitations of the system.)

My summary: Looks really cool. I would buy them and play with them. If they didn’t cost $160 for a base set. Just too pricey for me. But, if I’d seen these before buying littleBits, I would definitely compare the two systems before starting on one.