Pi Day is the celebration of the mathematical constant π, but it is also a day for scoring pie deals. That includes pizza, sweet, and savory pies.

Pi Day is observed on March 14 (3/14 in the month/day format) since 3, 1, and 4 are the first three significant digits of π, reports The Guardian.

Pi-story

π is a Greek letter. The word “pi” is derived from the first letter of the Greek word perimetros, which means circumference. The Ancient Greek mathematician Archimedes is most commonly credited with being the first to accurately calculate the estimated value of pi.

“In mathematics, this infinite number is crucial because of what it represents in relation to a circle—it’s the constant ratio of a circle’s circumference to its diameter. Pi is also essential to engineering, making modern construction possible,” reports History.

Pi Day happens to be Albert Einstein’s birthday.

Pie Deals

Pie is round, and pi is a mathematical ratio that represents a circle’s circumference to its diameter. Pies around the world have rich histories, including key lime pie, which was invented only because a baby died on a transatlantic voyage.

Pi Day is a fitting opportunity to hold a pie eating contest. eHow suggests rules surrounding common issues like hand-tying and vomiting. A pie baking contest is a less messy, and just as sweet, alternative.

Each city has its own Pi Day deals, but here are a few nationwide:

Bakers Square: This deal is a day later than Pi Day, but Free Pie Wednesday is every Wednesday. Get a free slice of pie with the purchase of any menu item.

Bertucci’s: Buy any one large pizza and receive a large cheese or Bertucci’s special pizza for just $3.14 using the discount code PIDAY online. This offer will be available for lunch and dinner, and will work through any ordering platform.

Bojangle’s: Ok, so these are rectangular. On Thursday, March 14, get three rectangular Sweet Potato Pies for $3.14.

Boston Market: Special buy-one-get-one deal on chicken pot pies on March 14. Print out a Pi Day coupon from BostonMarket.com and get a free rotisserie chicken pot pie with the purchase of another pot pie, and drink, at any one of the more than 450 U.S. locations.

California Pizza Kitchen: Get a slice of Key Lime Pie for $3.14. The offer is only valid at participating locations.

Hungry Howie’s: Get a medium 1-topping pizza for $1 with the purchase of a large 1-topping pizza at regular price. Order online and add the coupon code Medium1.

Kroger: Kroger offers fruit-based, sweet potato, pumpkin and no-sugar-added pies for $3.14, which is over 30 percent off their regular retail price.

Pizza Hut: Pizza Hut will release three math problems on its Hut Life blog: be the first person to solve and submit the correct answer for a chance to receive 3.14 years of free Pizza Hut pizza. All three problems will be released at 8 a.m. ET, March 14.

Milk Bar and Whole Foods Market also offer Pi Day deals.

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