Float and Sink Activity for Preschool Pre-K

Try this learning activity to help kids explore and discover which things float or sink. By freely exploring with materials, children learn the scientific process. They form their own questions about why something happens, and test out their own theories.

Remember to download the free Float and Sink journal page below!

Float and Sink Preschool Science Experiment

You can do Float and Sink activities inside or outside as a small group, or inside in the Sensory Table.

Materials Needed:
Tubs of water (one for every pair of children)
Small items that will float
Small items that will sink
Towels

Set Up:
Fill tubs with water. Gather float and sink items, and sort them into bowls or containers.

Procedure:
Give each pair of children a tub of water, and tell them they are going to test several things to see if they will float or sink. Pass each child a bottle cap, and ask them to make a prediction whether they think the cap will float or sink. Ask them to place the bottle cap in the water to see what happens. Have children test each of the items in the same manner, making a prediction first, then testing them. Do not pass out all of the items at once; instead, pass them out one at a time, randomly. Each child gets their own item to test in the water, but each pair of children shares a tub of water.

Examples of things that sink:
Pebble
Penny
Marble
Metal spoon
Key
Seashell
Paperclip
Button
Toy fish (like a math manipulative fish)

Examples of things that float:
Bottle Cap or Lid
Feather
Unifix cube
Small piece of paper
Sponge
Plastic Easter egg
Rubber duck
Leaf
Toy boat
Empty bottle (with cap on)
Crayon
Cork
Pool noodle piece
Wooden craft stick (popsicle stick)