19. Pi Day (March 14th)
People celebrate this delicious mathematical day worldwide. Why? To celebrate the importance of Pi aka π, which is the Greek equivalent. If you are not sure what it is, mathematicians use the symbol Pi to represent a constant, the ratio of a circle’s circumference to its diameter. No matter the size of the ring, the distance around the edge is more than three times the distance across. Pi is nothing new; it’s been around for over 4,000 years and studied by many mathematicians, like Newton, Leibniz, and Fibonacci. Some even spend most of their lives calculating and looking at Pi.
What’s cool about Pi Day is that math enthusiasts, and anyone else who cares, love to recite out loud and on the internet the infinite digits of Pi, which starts with 3.141159, etcetera. There is also lots of chat about math with friends and strangers while eating a good piece of the pie. Researchers have even found rope marking places where buildings estimated pi to be 3.125 in ancient Babylon. Even Egyptians determined the ratio, which was mainly based on measurements. So if you love math and everything to do with Pi and delicious pies, then this is the anniversary that needs to be on your calendar.