Penny Circles

These labeled circles are a physical version of this quadratic modeling activity where students graph the number of pennies (or nickels) that fit flat in a circle with the diameter of the corresponding circle.

When printing for a classroom, it's best to have a complete set of rings for each group but groups can also share if you don't have enough for that.

I like to print the final few layers in a different color to make the diameter labels stand out.