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Seeing Pi Activity

All you need for this “Seeing Pi Activity” is a tube of tennis balls. Which value is greater – the height of the can of tennis balls or the circumference of the can of tennis balls? The answer might surprise you or your students!

seeing pi activity with tennis balls

I closed out each class period with an activity called Seeing Pi.

photograph of tube of tennis balls on smartboard with title "Seeing Pi"

Seeing Pi asks a thought-provoking question.  Which value is greater – the height of the can of tennis balls or the circumference of the can of tennis balls?

To me, the answer is obvious.  But, my first instinct was wrong.  Try writing out a mathematical expression for both.  You might just be surprised, too!

In one of my classes, my students refused to believe the mathematics.  We ended up cutting a piece of string the length of the circumference and holding it up to the tennis ball can.  This made believers out of them!