Sink or Float? A Hands-On Science Investigation

Student Task

• Set up a clear tub of water and a tray of objects: a cork, a coin, a leaf, a stone, an apple, a metal spoon, a sponge and a marble.
• Children make predictions in activity 1 before testing, then record results.
• Do the clay boat test together, then children complete activities 3 to 5; answers are in the answer key.

Classroom Use

• Clay boats: give each group a ball of modeling clay and challenge them to make it float, then count how many paper clips their boat can carry.
• Orange test: an orange floats with its peel on but sinks when peeled. Ask children to predict first.
• Mystery objects: children bring one object from home to test the next day.

Differentiation

Support: use picture cards for each object and a simple yes or no prediction. Challenge: ask children to find two objects of the same size where one sinks and one floats, and explain why.

Answer Key & Assessment

Activities 1 to 4 check predicting, recording and sorting (answer key included). Activity 5 checks reasoning about shape.

Learning Objectives

• Predict, test and record whether objects sink or float.
• Compare results with predictions and describe what they found.
• Explain that the shape of an object can change whether it floats.

Teacher Tips

Let predictions be wrong and celebrate them. Ask "What surprised you?" rather than "Who was right?".

What's Included

• 6-page printable PDF lesson pack: teacher lesson plan with timings, materials and differentiation
• Key vocabulary list (4 words with meanings and examples)
• Student worksheet (5 activities)
• Editable Word version of the worksheet
• Complete answer key (also as a separate PDF)

Additional Files

• Editable Worksheet (Word) (DOCX)
• Answer Key (PDF) (PDF)

Teacher Reviews