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Pi is the ratio of a circle’s circumference to it’s diameter.
Think of the circumference as the distance around a circle, and the diameter as the distance across it.
Pi is a mathematical constant. That means all circles, no matter their size, have this in common: the circumference is a little more than 3 times more than the diameter — about 3.14159265359 times more, to be precise.
Celebrate Pi Day — March 14, or 3-14 — by conducting your own search for pi.
To do your own test to see if the circumference of an object divided by its diameter really does always equal about 3.14, try this activity adapted from Layers of Learning.
What you need:
- Cylindrical objects (cans, spray cans, coffee canisters, ChapStick, etc.)
- Tape measure