The infinite evolution of π Day

In the student newspaper at Downers Grove South High School in suburban Chicago, Elsa Kramer lists the top five “pies” for π Day.

The digits of $pi; at the Maryland Science Center, March 2015 (Voxitatis)

They are: spinach, lemon meringue, key lime, French chocolate silk, and banana cream. About her top choice, she wrote, “I grew up eating bananas a lot, and noticed early on that there is a significant lack of mainstream banana-based desserts in this world. Now, a banana cream pie has an authentic, incredible banana flavor, with a thick, creamy consistency that pairs wonderfully with the graham cracker crust. I think banana cream pie deserves a little more love in this world.”

Then there are schools that celebrate the day not with desserts but with donations. At Fort Collins High School in Colorado, Brooklyn Beaudin reports that students can purchase the opportunity to “pie” their favorite teacher, all in an effort to raise money for the McKinney Vento program, which stems from a federal law that ensures immediate school enrollment, stability, and support for children and youth experiencing homelessness. A worthy charity deserving recognition everywhere, but again, not really related.

The mathematical — and original — meaning of π Day, is neither as subjective as a favorite dessert nor as heart-rending as a worthy charity. It includes that irrational number that math folks celebrate once a year.

Conan Rae at Dinuba High School just down the road from Fresno, California, claims the π Day tradition was started by physicist Larry Shaw, often affectionately called the “Prince of Pi,” at San Francisco’s Exploratorium.

Shaw indeed sparked the tradition: In 1988, he organized the first official celebration at San Francisco’s Exploratorium, where he and his wife set out fruit pies and tea for museum guests at exactly 1:59 PM — a nod to the next three digits in the sequence (3.14159). Shaw’s legacy of “walking in circles” and celebrating curiosity has since turned a niche physics prank into a globally recognized holiday.

Conan also claims that a computer calculated the mathematical constant, which represents the ratio of a circle’s circumference to its diameter, to over 27 trillion decimal places back in 2021.

We can confirm that, too, although the 27-trillion record has been obliterated. Just this week, on March 13, the tech company StorageReview announced it had successfully pushed the constant to a staggering 314 trillion digits. The feat took 110 days on a single high-performance server, requiring roughly 2.1 petabytes of data, which is enough to overwhelm nearly any standard hard drive.

So, whether you’re throwing a pie at your favorite teacher’s face, enjoying a fruity dessert, or watching a server churn out way more digits than any real-world application would need, π Day remains a testament to the infinite nature of human curiosity. As the Class of 2026 moves toward graduation, these traditions serve as a final reminder that while high school may end, the search for the “next digit” in our personal and academic journeys never truly stops.