Every year on March 14, math lovers and pie aficionados come together to celebrate a unique holiday called Pi Day. Why this date, you ask? Because the date 3/14 matches the first three digits of the mathematical constant Pi (π), which is approximately 3.14. But what is Pi? Represented by the Greek letter 'π,' Pi is a number that is used when dealing with circles. It represents the ratio of a circle's circumference (its edge) to its diameter (the distance across the center of the circle). This number is the same for all circles, no matter how big or small they might be! Pi is not a recent discovery. People have known and used Pi for over 4,000 years! Different civilizations, from the Ancient Egyptians to the Babylonians, had their own approximations of Pi. Aside from its mathematical importance, Pi Day is also famous as the birthday of Albert Einstein, one of the greatest scientists in history. To celebrate, some people eat pies or hold competitions to see who can remember the most digits of Pi. So whether you're a math whiz or just someone who loves a good pie, Pi Day has something for everyone!