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Lesson Plan #: AELP-SCI0025
Submitted by: Dawn Nelson
Email: DNelson398@aol.com
Date: November 9, 1998

Grade Level(s): 3


  • Science

Duration: 45 minutes

Description: Students will recognize what makes a clay ball float.

Goals: experiment with clay to recognize what makes something float


  • Students will understand the role that air plays in floating.
  • Students will make the necessary modifications to keep objects afloat.
  • Materials: container, water, balls of clay


  • Show the students a ball of clay. Ask them what they think will happen if you drop it into a container of water.
  • Drop it in the water. Ask them why they think it sank.
  • Give one ball of clay to each student. Tell them to mold their clay into a shape that will make their clay float.
  • Encourage them to keep trying. Sometimes, depending on how much time is left, I let the students use pennies. They count how many pennies their clay boat can hold. I make it into a contest and at the same time they realize how to modify their boat when it sinks.
  • Assessment: After many have achieved their goal and their clay floats, draw some pictures on the board.

  • Ask which picture of the clay will float and which one will sink.
  • Ask why did certain ones float. Ask if there is anything inside of the boat and if that has anything to do with the clay floating.
  • Discuss that the ones with the higher sides trapped more air inside and floated.
  • Follow Up:

    I usually follow this lesson up with using everyday materials and predict and test if they float. I also discuss submarines and what makes them float and sink. There is a really cool experiment with simulating a submarine using a 2-liter soda bottle with holes in it connected to a tube (usually the tubing for a fish tank works great). They love to blow in the bottle and watch it rise out of a container of water!

    Internet Resources:

    • Bill Nye The Science Guy Episode Guides Episode #05: BUOYANCY http://www.billnye.com
      To locate the information, click on the link for Episode Guides, then Physical Science, then Physics, then Buoyancy.
    • Maverick Boats: Paper Boats http://www.highhopes.com/maverickboats.html