The Life of Pi!

Pi

π

apporximately 3.14159265

What is this mysterious number? How was it found? And why is it important?

Pi is an irrational number (meaning it can't be expressed by a fraction) that represents the ratio of a circle's diameter to its circumference. This allows us to easily find the circumference and the area of a circle using a couple of easy to remember formulas:

Circumference = π times Diameter
Area = π times Radius (half of the diameter squared) squared

Pi is obviously very important to mathematics as it allows us to easily make calculations about one of the trickiest shapes, the circle! The history of Pi is almost as long as the history of math itself. The ancient civilizations of the world had a rough understanding of Pi, and it's even mentioned in the Bible. However, it wasn't until the Greek mathematician Archimedes did extensive research on the subject that we got close to the number we currently use today. By inscribing circles into polygons, he managed to find a common ratio. As the study of Mathematics has advanced, so has our understanding of Pi, and today we can calculate Pi to over 2 TRILLION digits.

Fun Pi Facts: The world record for remembered digits of Pi is 67,890 digits, held by Lu Chao, a 24-year-old graduate student from China.

Pi Day is held every March 14th (3/14, notice something?). There are many ways to celebrate Pi Day: Singing songs about the subject, baking Pi pies, calculating the circumference and area of circles, etc! March 14th is also Albert Einstein's birthday.

This video by "Pi Diddy" is one example of a Pi Day celebration song!