Another Pi Day is upon us, bringing with it all the mathematics lessons, eating contests, and irrational puns.

For those who need a refresher, the holiday commemorates not only the 16th letter in the Greek alphabet — π — used in mathematics to represent the ratio of the circumference of a circle to its diameter, but also Albert Einstein’s birthday. Take a second to appreciate that coincidence.

Of course, pi represents an infinite number of digits starting with 3.14, which is also the official date of the holiday.

The number has inspired these Pi Day events around the world, from recitation competitions at universities to pie eating contests. While 2015’s events got much of the spotlight because 15 is the next two digits of the infinite number (*3.1415…*), this year the holiday lands on a Monday and many of the universities, where the bulk of celebrations tend to take place, are on vacation.

That said, Pi Day perennially offerse biggest and strangest Pi Day events happening around the globe his year.

### Universities

Princeton University in New Jersey, without a doubt, holds the biggest celebration of the holiday anywhere in the world, with a weekend-long celebration of events including lectures, pie-eating contests, and front row seats to watch Sebastian James attempt to break the American record of 20,000 digits of pie over the course of three hours.

But most impressively is the town’s dedication to Einstein’s birthday. The town became a home to him after the math and science genius fled Germany and the town is making sure that is commemorated with punny, over-the-top events on his birthday.

### Pi Day 5K

This annual event can be done anywhere, simply register, go for a run, and you’ll receive a medal and t-shirt in the mail. Since it’s more of an individual race, you’ll want to make sure you share it on social media, or else it’s like it never happened.

A 5K is technically 3.1 miles, but the organizers encourage participants to stretch for those extra 4 hundredths for Pi Day. Visit pi5k.com to register.

### Actual Pi(e)

Four & Twenty Blackbirds, the sweet pi shop in Brooklyn, New York offers three pies for $14. Get it, because Pi is 3.14? Keep up people. Pun pricing or not, one look at these photos and it’s obvious this deal will be worth your time.

Surely there are a number of pie eating contests wherever you live, which could include Humble Pie Company’s competition in Providence, Rhode Island, or the contest in Seattle’s Westlake Park.

### Geocaching

In Florida there’s a Geocaching search starting at 6:30 p.m. on Monday. Discover hidden items, participate in Pi related trivia and win prizes through the community organized scavenger hunt.

### Pizza Pi

There’s more than one kind of pie out there and pizza pies have to be among America’s favorite. Blaze Pizza, with locations all over the United States, celebrates with a $3.14 pie offered on the day.

That’s an exciting offer, but Pizza Hut is awarding customers 3.14 years of free pizza — if they can answer three math questions devised by Princeton mathematician John H. Conway.

Here’s the catch — the three questions range from high school to Ph.D. level. The company will distribute the questions online at 8 a.m. eastern time today, and three winners will be chosen from the pool of people able to answer all three. That is, if anyone can.

“Pi may be irrational, but free pizza is anything but,” says Conway in a statement. “I’m eager to challenge America with these problems and find the next great pizza-loving mathematician that can solve them.”

Pizza Hut estimates the award is worth $1,600 in gift cards.