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Floating City – STEM Challenge for Kids

Can you build a Floating City? STEM challenges don’t get much easier or more fun than this. This fun activity only requires simple materials and young children will have so much fun trying to build their own city. You’re preschoolers and kindergarteners will have a blast watching as their towers come crashing down into the waves.

When these foam blocks get wet, they stick together thanks to surface tension. This means that you can make buildings that float. But the water inside the tub moves and makes the base of the building unstable. How do you change the design of your building so that the small waves won’t knock it down?

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More Engineering Activities for Kids

Are you looking for some more simple STEM activities for little learners? An engineering challenge is a fun way to help younger kids develop critical thinking while they play. Here are some different ways to introduce your preschoolers and kindergarteners to structural engineering.

  1. DIY Magnetic Ball Run
  2. Building Shapes – STEM for Kids
  3. Parachute STEM experiment
  4. STEM Challenge: DIY Pirate Ship
  5. Building with Straws – STEM Challenge
  6. Build a Paper Chain

For more ideas, check out these other 25 STEM Challenges for Preschoolers.

Materials Needed

  1. A large plastic tub
  2. Water
  3. Foam building blocks


How to Make a Floating City

Step 1. Fill a large plastic container with water.

You don’t need too much water, just enough to cover the bottom of the tub with at least 2 inches of water.

2. Put the foam blocks inside.

3. Try and build a structure that doesn’t fall down.

How high can you make a tower before the moving water knocks it down? This is a great stem activity for younger and older kids alike. Because the complexity of the design can increase as your child gets older.

You’re going to need to experiment with different structures, developing problem solving and engineering skills as you go. What happens if you make the base wider? What happens if you focus on making it higher? Can you build a bridge between two different shapes?

This is a great way to play and learn on a warm sunny day, or even in the bath.

Are you going to try this Floating City activity with your kids?
Don’t forget to pin the idea for later.