Why is pi, a number we represent with the symbol π, so important? Well, it’s literally one of the foundations of our society. In fact, every civilization had to figure out pi. The Greeks, Ancient China, India, Egypt, the Babylonians, all worked hard to calculate it as precisely as they could. How old is it? Archimedes figured out a way to calculate pi over 2000 years ago and the ancient Egyptians and Babylonians may have used pi long before that.