You will need:

  1. Ruler
  2. Pencil
  3. Two plastic or paper cups
  4. Water


  1. Lay the ruler over the pencil to create a seesaw.
  2. Fill the cups with water so they are two thirds full, then balance them at either end of the seesaw (make sure they are sturdy and not going to fall over).
  3. Now, without touching either cup, dip your finger in one cup and watch as that side goes down. Dip your other finger in the other cup. As you alternate your dipping, you will be able to control the motion of the seesaw.

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