Pi is something we all learned about in school, but if you need a refresher, don’t worry, we've got you. Pi is simply a circle’s circumference (the distance around a circle) divided by its diameter (double the length of any point on the circle to its center). It’s an irrational number that goes on forever without ever repeating itself, but most of us know it as 3.1415926535897, or simply 3.14.

Pi Day is celebrated on March 14th because in some nations, such as the United States, dates are often written as month/day. As far as the origins of pi, mathematicians have been trying to estimate the number for thousands of years. And Babylonians and Ancient Egyptians actually came quite close to figuring it out. But it wasn’t until Greek mathematician Archimedes and Chinese mathematician Zu Chongzhi started working on pi that we came to our most accurate approximations (without using calculus or computers). 

Pi Day also happens to be Albert Einstein’s birthday, so it’s the perfect day for math lovers around the world to celebrate the beauty of mathematics. And while the United States Congress first recognized National Pi Day in 2009, the holiday can actually be traced back to 1988.

Three years after Frank Oppenheimer’s death, staff of Exploratorium, which Oppenheimer founded, met at a retreat in California to soul search and brainstorm. During this retreat, former staff physicist Larry Shaw made the connection that March 14th could be linked to the famous number pi. Larry and his wife decided to then fill the Exploratorium museum with pies on tea to celebrate the very first Pi Day.  

To learn more about the importance of Pi Day, we reached out to Anthony Persico, Founder of Mashup Math, who was kind enough to have a chat with Bored Panda. “Pi (π) is a fundamental constant in mathematics, representing the ratio of a circle's circumference to its diameter,” Anthony shared. 

“This relationship is significant because it applies to all circles, large and small, making pi incredibly useful in the fields of mathematics and engineering. And, since pi is an irrational number, its decimal representation is infinite, making it a fascinating concept beyond mathematics,” he explained.

We were also lucky enough to get in touch with Candice of Proportional Plate. Candice is a retired mathmetician and full-time food blogger, so she knows plenty about pi and pie! “Pi is a mathematical constant and the foundation for countless crucial formulae across math and science that help us understand our world,” Candice shared. 

“Pi holds many memories for people from when they first learned about it in their school days, and I think it’s rare that a mathematical concept becomes such a mainstream and widely known reference, let alone to the point that it has its own ‘day.’”

As far as how Anthony chooses to celebrate March 14th, he shared, “Pi Day is arguably the most mathematically significant day of the year, and we always celebrate! We typically like to share some fun facts about Pi Day (for example, Albert Einstein's birthday is on Pi Day), work on a fun circle-themed math puzzles, and, of course, eat delicious circular foods such as pizza, pie, and cookies. We also have an annual competition to see who can memorize the most digits of Pi.”

Candice also explained how she likes to spend Pi Day. “I studied and taught mathematics for many years, and now I am a food blogger, so Pi Day has a unique significance for me,” she shared. 

“It’s funny that at some point, maybe solely because of the homophone ‘pie’ and ‘pi’, a trend started to share pictures of pie on Pi Day instead of anything math-related. My favorite way to honor Pi Day is to use the day as a celebration of my love of math. It’s an opportunity to learn a new mathematical concept, start a new book, or do some math puzzles,” the blogger says.

And if you’re looking for a way to celebrate today, Anthony says, “You can celebrate Pi Day by baking and/or sharing pies with friends, classmates, or family members. If you want to make the day extra special, you can start your celebration at exactly 3:14 pm to represent the mathematical approximation of pi (3.14).”

“Pi Day is not just for math enthusiasts,” he added. “It is a holiday that everyone can enjoy and join in the celebration of the history, beauty and mystery of mathematics and how it shapes our world and our understanding of the universe.”

“There’s nothing wrong with indulging in some pie on Pi Day, and it would be awesome if we could always marry that with a tradition of sharing knowledge!” Candice told Bored Panda. “Pi Day is a great chance to share a fun math fact or puzzle with a loved one, share recommendations of math books or websites to check out or learn a new piece of math history. You could even share a time when math blew your mind!”

“I’d encourage everyone to check out the official Pi Day website and dedicate even just 5 minutes to learn more about it,” she added. “And if you have a delicious piece of pie to enjoy while you learn, all the better!” 

Do you plan on celebrating Pi Day today, pandas? Whether you have big Pi Day plans or you’re simply staying at home and eating leftovers today, we hope you’ve enjoyed scrolling through these wholesome pics. Keep upvoting the ones that make you love math a little bit more, and then feel free to check out another Bored Panda article featuring pies right here!