Online Science Class for Preschoolers: Float or Sink?

WEEK 4: Oceans

Day 2: Float or Sink?
Overview: This lesson lets your child experiment with the concept of floating and sinking.  Children predict and experiment.  The lesson appeals to the Verbal-Linguistic, Logical, Visual-Spatial, Bodily-Kinesthetic, Naturalist, and Intrapersonal intelligences.

  • a sponge or two
  • balloon (water balloon if you can blow it up; normal balloon if you can't blow up a water balloon)
  • bucket or pan that will hold about a gallon of water
  • outdoor area to collect things to test
  • toys that can get wet
  • egg
  • cup
  • salt
  • paper towels
  • Science Journals.  

  • Gather supplies.  
  • Blow up balloon.
  • Pour about a gallon of water into the bucket.  Water should be several inches deep.

Science Time!
  • Today we're going to experiment with floating and sinking.  Remember the sponges from yesterday?  Do you think sponges will float on top of the water or sink to the bottom? Let your child find out.  
  • What about a balloon?  Again let your child test this.  Older children may enjoy repeating the experiment with  a balloon filled with water.  Would a half-full balloon have the same result?  Fish have an organ inside them like a balloon.  When they want to move up in the water they fill it with air.  When they want to sink they empty the air. 
  • What toys do we have in the house that will float?  What toys do we have that will sink?  (Alternatively you could present a pile of toys and ask your child to sort them into two piles:  a pile she thinks will sink and a pile she thinks will float.)  Let your child test the toys and find out if they really sink or float.
  • Do you think a stick will sink or float?  Let's find some other objects outside to test.  Go outside.  Pick some objects to test.  Let your child predict first, then test.
  • What about an egg?  Carefully let your child test an egg in a 6-8 ounce cup of water.  (The egg should sink...unless it is rotten.)  Remove the egg and stir in 3-4 heaping spoonfuls of salt.  Let your child try again.  If it sinks again, add more salt and repeat.  The ocean is full of salt.  Many things float in salt water that will not float in fresh water.
  • Science Notebooks:  Draw or write about what we did today.


Nicki Woo July 2, 2011 at 9:53 AM  

I love science! What a fun idea to help kids love it to. And the ocean. . .nothing can be more mysterious and wonderful. Thanks for sharing. I'm your newest follower.

Jansen Family July 2, 2011 at 8:27 PM  

Nicki, I love science and oceans too! They are both such fun subjects for kids! Thanks for stopping by!