Updated March 11 2026
Pi Day was first formally celebrated in 1988 at the San Francisco Exploratorium, when staff physicist Larry Shaw organized events around March 14, or 3/14, aka 3.14, which are the first three digits of pi (π), the mathematical constant that is the ratio of a circle's circumference to its diameter. In 2009, the U.S. House of Representatives recognized it as an annual event, and since then, much like pi itself, has become a source of infinite joy.
These Pi Day lessons and activities are perfect for teaching your students about trigonometry, geometry, physics, cosmology, statistics, thermodynamics, and much more as pi appears in numerous formulae. So help yourself to a slice of pi here and enjoy!
Pi Day Lessons & Activities
Pi Day Challenge Games
A fun and quirky set of math/logic games that are slightly addictive. Practice with the 24 puzzles from 2025 or the archive dating back to 2017, while the Pi Day Challenge Team prepares the new 2026 problem set. Adding to the fun is the inclusion of ancient mythology, history, art, and ordinary circumstances, such as traffic jams and bread recipes. Create a free account or login with Google.
NYT Learning Network: Taxicab Geometry
What’s taxicab geometry, you may ask? Well it’s something along the lines of (sorry!) how an Etch-a-Sketch works—i.e., only vertical and horizontal moves are allowed. But it’s more complicated than that. And oh, by the way, pi equals 4 and circles aren’t round. Intrigued yet? This imaginative article dives into not only taxicab geometry but also related math topics. Questions and ideas for further exploration are provided. Free with no account required.
Pi-Search
Widely acknowledged to be completely useless for most purposes, Pi-Search is nonetheless absolutely required to fully celebrate Pi Day. The point of Pi-Search is simple: In less than one second, find any series of digits that occur in the first 200 million digits of Pi. A helpful odds table displays the likelihood that a series will be found, based on its length. For example, the eight-digit string commonly used to denote birthdays carries an 86% chance of being found within 200 million digits. What’s more, this humble (pi) site is packed with all kinds of other useless (and occasionally useful) information, such as how the search is actually performed and pi numeric trivia. Great fun.
Mensa for Kids: Pi Day Palooza!
Fine collection of Pi Day lessons and activities, including a homemade Spirograph, trivia, greeting cards, and even Pilish poetry. (If you’ve never tried writing in Pilish, you’re in for a keen challenge).
A Brief History of Pi (π)
Which has been around longer -- pie or pi? The answer may surprise you. Learn how ancient mathematicians deduced the concept and approximate value of pi in this article from San Francisco's Exploratorium museum.
14 Fun Pi Day Activities for High School Students
A lighthearted—yet academically challenging—collection of pi-related activities that incorporates music, language, poetry, art, statistics, history, American date abbreviations and more. For full appreciation of activity No. 3, “Throw a Pi-Themed Party,” students should watch Why is the area of a circle equal to π r² ? 2000 year old proof, but with pizza.
The Discovery That Transformed Pi
Before Isaac Newton transformed mathematics, the calculation of pi was laborious and slow. This entertaining, yet in-depth, video explains the principles underlying Newton’s elegant proof. And yes, there will be pizza.
NASA Jet Propulsion Laboratory Pi Challenges
Care for a bit of pi-in-the-sky thinking? Explore illustrated lessons that take pi out of Earth’s orbit in service of solving solar systems problems, such as the density of the asteroid Psyche and frost in lunar craters. A “stellar” collection.
Learn About Pi
A dynamic, illustrated explanation of pi that grabs the reader’s attention with its colorful, lively graphics which clearly demonstrate the properties of pi and how it can be used in calculating volumes of many two- and three-dimensional shapes. This webpage from PiDay.org would provide an excellent, clarifying accompaniment to the pi-related lessons included in this article.
Teach Pi
A plethora of pi activities, stories, music, lessons and trivia, TeachPi.org was founded by math educator and speaker Luke Anderson, whose enthusiasm for pi and numeracy cannot be contained. Be sure to check out Anderson’s alter ego, Pi Daddy, and his rap song, “Lose Yourself (In The Digits).” A super fun site to peruse.
PBS LearningMedia Pi-Related Resources
An abundance of K-12 pi-related lessons and interactives that includes calculating pi with darts, the square-wheeled tricycle, music from the Golden Ratio, and more fascinating topics. Lessons and activities are standards-aligned, shareable to Google Classroom, and include plenty of support material for teachers. And, yes, there will be pie. And pizza.
