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  • Writer's pictureJacobiP

Sink or Float - Science for Toddlers

Sink or Float is a perfect activity for summer that toddlers can enjoy, experiencing the sensory feel of water, splashing and playing while conducting a (very simple) scientific experiment!

At the same time, children will learn vocabulary, rules of physics and the difference between buoyant and dense objects.



What you’ll need:

  • Wide bowl filled halfway with water

  • Variety of water-proof toys and items to test, made of varied materials (such as: wine cork/wooden spoon/metal spoon/plastic ball/LEGO brick/popsicle stick/straw/toy car etc.)


3 Easy Steps:

  • Let your toddler choose an item from the pile and ask them to guess – Float or Sink?

  • As you go through the pile, discuss the scientific principle behind it: ask your child why she thinks some items float while others sink. She might think it’s because of their size or weight. Explain that items sink or float based on the material they're made of – i.e. their density.

  • To add more fun to the game, reward your child with a sticker for each successful guess. Or, in case of multiple participants, make it a competition! Create a chart, specifying right or wrong guesses, and give the winner a small trophy at the end… (depending on your child's love of competition…)



To make it simpler for your child to understand, you can explain: molecules are very, very tiny. You can only see them with a special microscope. In some objects, like a rock, molecules are squished tightly together. In others, like wood, the molecules are more spread out. How closely molecules are crowded together in a space is called density. Density is a why some things float and others don’t.




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