First Slice Pie Café in Chicago is offering a Pi Day deal at their Montrose, Manor and Andersonville locations. They’re offering slices of pie for $3.14, mini pies for $6.28 and whole pies for 20% off. Those who are in the store at 3:14 p.m. will also receive an "exclusive surprise," according to the shop's Instagram post.

Friday, March 14 marks Pi Day, a celebration of the mathematical constant that (roughly) equals 3.14. And in a shining testament to the United States' willingness to use anything as an excuse to eat calorie-dense food,

Years ago, the infinite decimal 3.14 or its Greek symbol pi was mostly known to math and science geeks, but now March 14 is also a day for tasty deals. Here’s a little history to whet the appetite. The first “Pi Day” celebration was held in San Francisco in 1988 when a physicist at the Exploratorium,