Use an animation program like Animation-ish to create an animation inspired by Pi. Check out this film created by high schooler Ben Reynolds. He created this in the middle level of Animation-ish in no time! Try Animation-ish free at: http://www.fablevisionlearning.com/animationish
Teaching Math Tip: Circular foods & teaching fractions don't always go hand in hand. Try teaching fractions w/ shapes w/ edges. The circle gets your basic 1/2 and 1/4, but try doing 3/4 and 1/8 or 6/8 and it starts to get tricky.