Although you may not have gotten the memo on this one unless you’re a giant math “enthusiast,” today is Pi Day, a nationally recognized holiday that honors both the famed mathematical constant, along with, in many places, the birthday of Albert Einstein (who would have turned 134 today).

Here are three (and a little bit extra) ways to enjoy the holiday:

1. In celebration of this most hallowed and nerdy of days, it’s customary for Pi Day revelers to consume delicious round treats most commonly including (but certainly not limited to) pies and pizza pies. The educational blog Instructables hosts a π-themed pie-baking contest, while many local pizza and pastry purveyors have special promotional sales deals today, like the DIY-inspired Georgia franchise Your Pie, which offers $3.14 pizzas.

2. If you want to test your brain power a little (and lose some friends), you can celebrate by trying to memorize as many digits of Pi as possible, using specially designed tools such as Eve Anderson’s Pi Trainer. If you're feeling up to the somewhat daunting task, you can also try reading up on the ponderous history of the irrational fraction. For youngsters, Manhattan’s Museum of Mathematics offers a pi-themed scavenger hunt for children ages 11 and up in the afternoon.

3. For cinema buffs, the holiday presents an excellent opportunity to catch up on some screen time with Darren Aronofsky’s 1998 mathematical thriller, “Pi.”

4. As a bonus for the truly dedicated: You can trek out to Einstein’s hometown of Princeton, N.J., where veteran celebrants can compete in an Einstein-look-alike contest or take a walking tour of his town. Tickets cost $3.14, and the proceeds go to the Paul Robeson Foundation.