Brenda Bautista

What is that funny looking symbol? It’s the Greek Letter Pi. It looks like a crooked little table! But it is important in math and physics and LIFE. Did you know that pi will help you figure out how much pizza you have? How big is your cookie? You can use pi to understand anything that is shaped like a circle.

Pi is an interesting number. It never ends! It starts out

3.141 5926 5358 9793 2384… but it just keeps going, and going, and going…Most of the time we shorten pi to a few digits. In this video we use 3.14, but you can use more digits if you like. In fact, some people make it a game to memorize as many digits of pi as they can.

In this video, our puppet friend Charlie celebrates Pi Day by learning about the definition of pi:

Pi is the ratio of a circle’s circumference to its diameter. This also means that if you know the circumference of a circle, you can find its diameter. Or if you know its diameter, you can find the circumference!

Pi is also in the equation for the Area