Grades 1–3
Floating: True or False?
Seven facts about sinking and floating to mark true or false, then explain how a heavy ship floats.
Science worksheet · Sink or float
Clay Boat Challenge
An engineering challenge: shape clay into a boat that floats and holds as many pennies as it can.
- Grade level
- Grades 2–5
- Time
- About 40 minutes
- Topic
- Sink or float
- Answer key
- Not needed: answers vary
- Kids practice
- Sinking and floating, Density, Predicting and testing
What kids do
Printed on the sheet:
- The challenge: a ball of clay sinks. Can you change its shape so it floats and carries cargo? You need: a ball of clay the size of a golf ball, a tub of water and pennies.
- Why does the ball of clay sink?
- Draw your boat shape.
- How many pennies did it hold?
- What shape I made
- What shape held the most pennies? Why do you think it worked?
Teacher tip
Let kids reshape and retest. The improved boat usually holds twice as much.
How to use it
- Set up a water tub with towels and let kids test real objects.
- Ask kids to predict and record before every test.
- Start with a two-minute “I notice, I wonder” talk about the picture on the sheet.
Watch for
Big things don’t always sink. Shape and material matter.
Talk about it
- Why does a heavy ship float?
- What evidence helped you choose your answer?
Take it further
Hold a boat-building contest with foil and pennies.
US Letter, prints well in black and white. Free for home and classroom use: print as many copies as you need.
More sink or float worksheets
Grades 3–5
Liquid Density Tower
Pour honey, dish soap, water and oil into a cup, number the layers from bottom to top and draw your tower.
Grades K–2
Sink or Float: Predict and Test
Guess whether eight objects will sink or float, test them in a tub of water and check your guesses.
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