Sink or Float Challenge
Ages 4–10 · ~10/15 minutes · Low mess
Materials:
-
Clear bowl with water
-
Various objects to explore density (coin, sponge, wood, etc)
-
Prediction chart/worksheet
-
Pencils for taking notes
-
Towel for spills
Steps:
-
Gather a variety of objects
Collect a mix of everyday items with different materials and sizes.
-
Predict before testing
For each object, students guess whether it will sink or float (and mark their prediction on a chart).
-
Test one object at a time
Gently place each object into the bowl of water and observe what happens. Does it sink to the bottom, float on top, or float partway submerged?
-
Record the result
Mark the actual result next to the prediction. Discuss: "Was the guess right?", "Why might it have been different?"
-
Group Discussion
Talk about what the floaters have in common, and what the sinkers have in common. Introduce the word "density" as the explanation.
