Trundle wheel experiment  to help students understand the relationship of what a formula is and how they are derived.

  1. Have students determine the circumference of a circle (we used a record) using a string and ruler or the equation then compare.
  2.  Build a trundle wheel from the record (with now known circumference).
  3.  Measure a marked distance on the floor with the trundle wheel and a straight ruler. Compare the two results and talk about error.

Materials:

  • Record
  • Making tape (to mark the record and to attach dowel)
  • Wooden dowel

 

Finding pi.

  1. Cut out varying sized circles.
  2. Have students determine what pi is equal to based on their circle
  3. Measure the circumference and the diameter.
  4. Compare classroom answers. Discuss role of constants.