This is part of my 15 minute focus series of preschool science activties.

While they finished up lunch, I read the book Dem Bones. As I read about each joint, I had them use theirs – like wiggling toes and then bending/flexing their foot when we read about the toe bone and the ankle bone. (Optional: To better illustrate how our bodies work, I used a hinged Lego door to show how some joints (like knees and elbows) bend one way but not the other. I used the Zoob building toy to illustrate ball and socket joints. And I used two pencils side by side to show how the two bones in your lower arm pivot around each other when you twist your wrist.)

Then I gave them some small items (pompoms, feather, a bit of yarn), and encouraged them to show me if they could pick them up. (As four year olds, they can all pick up all these items, but I think they also have a sense that they used to not be able to do this, so are a little proud of themselves for this skill.)

I helped them notice the pincer grasp – how they have to bend the index finger and thumb toward each other to create it to help them pick things up. Then I asked “what would happen if you couldn’t bend your finger?” I taped a popsicle stick to the back of each child’s index finger to hold it straight. Then we tried picking things up and tried holding a pencil. It was really hard! (The funny part was that while our older 4 year olds and 5’s did this experiment and really had a-ha moments, our younger 4’s would just use the other untaped hand to do the job. When I told them to use their taped hand, they looked quizzically at me with a “why would I do that” approach.)

We untaped their fingers, and I had them practice using scissors or tweezers for a moment, and had them notice how their thumb moves away from their fingers to do that work. We talked about opposable thumbs and that many animals don’t have them. I asked “what would it be like not to have an opposable thumb?” Then we taped their thumbs to the side of their hands, and tried doing a variety of tasks (scissors, folding paper, writing, Duplos, tearing tape, taking a lid off a water bottle and putting a straw in). I also had a toddler busy board they could try.

Most of the kids really enjoyed the activity and got a lot out of it. A few did not like the experience of having their finger taped and thus having limited mobility and they opted out of taping their thumbs, which I OK’ed, because bodily consent is important to respect.

Find more Human Body and Skeleton themed activities.