Pi, of course, is the ratio of the circumference of a circle to its diameter, and on March 14th, math enthusiasts across the United States will come together to celebrate Pi Day. In Philadelphia, we’ll be celebrating in some slightly irrational ways, with many more desserts and circular foods than usual.

Day By Day

2101 Sansom St.

Philadelphia, Pa. 19103

(215) 564-5540

www.daybydaycatering.com This somewhat under-the-radar catering company in Rittenhouse Square also does lunch and brunch. In honor of Pi Day, they’re offering a variety of amazingly delicious-sounding pies, including Chocolate Stout, Vegan Grape Fig, Blood Orange with Pistachio Crumble and — prepare yourself — BACON CRACK. Yes. Bacon Crack. While they all sound great, you had us with just three little words…

Flying Monkey Bakery

Reading Terminal

51 N 12th St.

Philadelphia, Pa. 19107

(215) 928 – 0340

www.flyingmonkeyphilly.com For a wild take on pie, head to Reading Terminal’s Flying Monkey, where you can find an array of innovative whoopie pies and even a unique pie/cake hybrid. The former are a nod to an old Pennsylvania Dutch tradition and consist of flavored cream (pumpkin, peanut butter, strawberry and many more) sandwiched between two round cookies or pieces of cake. The latter is a Flying Monkey creation, Pumpple Cake, that’s made by baking slices of both pumpkin and apple pie inside of a chocolate and vanilla cake. It’s difficult to explain, but that’s all the more reason to try it for yourself!

The Franklin Institute

222 N. 20th St.

Philadelphia, PA 19103

(215) 448-1200

www.fi.edu Head over to The Franklin Institute to explore four floors of math, science and discovery. At exactly 3:14 p.m. on March 14, make sure to make your way outside to the front steps, where 314 plastic balls will fly into the air and guests can enjoy one of 314 (free!) pi-shaped soft pretzels. Tasty AND educational.

Grey Lodge’s Pi(e) Day

6235 Frankford Ave.

Philadelphia, PA 19135

(215) 825-5357

www.greylodge.com Grey Lodge, in northeast Philadelphia, is a two-floor bar known for its many beer celebrations. On March 14, it’ll be serving up pot pies with both turtle and mixed berry pies for dessert. There will also be a contest, awarding winners a “sweet prize” for reciting the most numbers of pi, as well as Pi(e) Trivia. And don’t forget to enjoy a brew or two from Yards, which is the event’s partner.

Linvilla Orchards

137 W. Knowlton Rd.

Media, Pa. 19063

(610) 876 – 7116

www.linvilla.com Linvilla’s beloved bakery started out selling only pies back in the 1960s, and 50 years later, they’re still as delicious as ever. Aside from classics like Dutch apple crumb (a favorite!), pumpkin, cherry and coconut custard, keep your eyes peeled for seasonal slices such as chocolate chip pecan and sweet potato crunch among the more than 40 varieties available. And in the fall, don’t miss Linvilla’s legendary apple cider donuts.

Magpie Artisanal Pies

1622 South St

Philadelphia, Pa.

www.iluvmagpie.com On Pi Day, what could be better than an entire restaurant devoted to pie? Short answer: nada. All of the sweet and savory confections at this South Street spot are stuffed full of local, seasonal ingredients (when possible) that, when paired with a super-flaky crust, add up to a couple slices of heaven. Got a sweet tooth? Try baked deliciousness like Lemon Curd or the unofficial signature pastry, Bourbon Butterscotch. Rather stick with savory? Go with the macaroni and cheese pot pie or a classic chicken and biscuit pot pie. And on Pi Day, Magpie will be offering slices of Bourbon Butterscotch for (you guessed it!) $3.14.

Percy Street Barbecue

900 South St.

Philadelphia, PA 19147

(215) 625-8510

www.percystreet.com Get your nerd on while devouring some of the most delicious pies in the Philadelphia area (calculating the actual pi of the pie is optional). Percy Street Barbecue is a 2011 Best of Philly winner for best pies from Philadelphia Magazine and serves up favorites such as pecan, key lime, chocolate mud and good old American apple pie. Stop in to Percy to make your Pi Day a little sweeter.

Pi Day Princeton

Princeton Public Library

65 Witherspoon St.

Princeton, NJ 08542

(609) 924-9529

www.pidayprinceton.com If you want to take a short drive, the town of Princeton hosts an annual Pi Day events extravaganza. Since Pi Day also coincides with Albert Einstein’s birthday, there are additional Einstein events to be enjoyed. Take advantage of events including pie-eating contests, an Einstein look-a-like contest, a kid’s violin contest, the math Olympics and more. This day of celebration used to be limited to the college but has now expanded to the general public. Events begin on March 13 and run through the 15. Related: Top Spots For Computer Classes In Philadelphia