Coin Tower Challenge: Discovery at Home

What you need:

  • Coins of the same size.
  • Thin cardboard (make sure the cardboard is thinner than one of your coins).


  1. Stack the coins on top of each other to create a tower.
  2. Use a piece of thin cardboard to remove the coin at the bottom of the tower. Hint: Speed is important.
  3. Remove as many bottom coins from the tower as possible before the tower falls!

Ways to expand:

  • Use different sized coins in the tower. Do the different sized coins make it easier or harder to remove the coins?
  • Create a structure that has multiple towers and/or a more complex structure. Try to remove the bottom coins without the tower falling.

What kids learn:

  • Experimentation! When kids experiment, they're learning how to learn. Failure is an important part of experimenting, so let kids try things that won’t work. It’s how they figure things out!
  • Hand eye coordination. Young children can use activities to help improve communication between their minds and bodies.
  • Basic engineering skills. Engineers solve problems with constraints, in this case, friction and inertia. They learn to solve problems by using the engineering design process: asking questions, coming up with solutions, building, testing and improving.


  • Constraint. A limitation or restriction. Materials, time, and space are common constraints. Real engineers have to work around constraints all the time!
  • Force. Energy caused by a push or a pull. In this case, the pull created by gravity and the stack of coins.
  • Newton’s First Law of Motion. Every object will continue moving at the same speed or remain still unless something makes it change.
  • Inertia. The resistance of an object to change its motion or direction.
  • Friction. A force acting in the opposite direction. When two things rub together they cause friction.