This is part of my 15 Minute Focus series. It can be used as a follow-up to our session learning the Scientific Method with a sink/float test.

Objective: children should be able to illustrate how something that would normally sink can float if it is put inside a “boat.”

Supplies

bowl of water; a collection of several small identical items that will sink (like glass stones or pennies or washers/bolts); a plastic dish / plate or styrofoam tray or toy boat that will float, foil (optional), towel

Activity

Sing “first we think up lots of questions”.

Say that our question today is: “will a [penny] float?”

Pass an item around so they can “observe with all their senses” (sing the verse as it passes). Ask them to make a hypothesis about whether it will sink or float. (sing hypothesis verse) Show that it sinks.

Then say “Do you think this dish will float? If so, give me a thumbs up. If you think it will float, give me a thumbs down.” Test their guess.

Then show them how if you put one [penny] in the dish it still floats! Ask them to predict how many [pennies] will float in the dish. Sing “do an experiment to test our guesses.”

Then test it. You can play around with ideas like if we put all the weights on one part of the dish it will capsize, but if we carefully distribute the weight, the dish will float longer.

Optional: demo how to make a boat with foil and see how many stones will float in it.

At the end, sing “hooray we learned something.”

Optional Extension

If you still have time, and a large container for water (like a sensory bin or multiple tubs). they could all try making foil boats and seeing how many pennies they can float.

Books

Try Who Sank the Boat? by Allen. YouTube  One by one, a cow, a pig, a donkey, and a sheep climb into a boat. Will it sink? When will it sink? Or What Floats in a Moat? by Berry and Cordell. YouTube. This is not just a book about sinking and floating, it’s also a good book about inventors It’s a fun rollicking read-aloud. Archie the Goat wants to cross a moat. He muses that a barrel might float.

Find lots more sink or float experiments here.