Happy Pi Day! March 14, or 3/14, represents the first three digits of pi, an essential constant in math that represents the ratio of a circle’s circumference to its diameter. This has important meaning even to those of us who aren’t math geeks: Restaurants and retailers mark the occasion with promotions featuring special prices on pies or on pizzas. You know, pizza pies, but they’re also both round foods.

Blaze Pizza: All day today, every pizza will cost $3.14. You don’t need a coupon, but the limits are that only one pizza in your order can be this price, and you have to order in the restaurant. The Houston Airport, Staples Center, and Disney Springs restaurants are excluded.

Boston Market: Get a free chicken pot pie with the purchase of another meal and drink. Must present coupon.

Half.com: You can get 95% off a paperback copy of the book Life of Pi today.

Hungry Howie’s: A medium pizza will cost $3.14 with an order of Howie Bread, as long as you order it online and pick the pizza up yourself.

Pieology: Get a customized pizza for $3.14. You’ll have to sign up for the chain’s “Pie Life” mailing list before you visit the restaurant. Check ahead to make sure that the location you’re visiting is taking part, since a number of them in California and Arizona aren’t.

Stevi B’s: Get an “infinite buffet” for $3.14 with the purchase of a drink.

ThinkGeek: Get a free Pi Day t-shirt with a purchase of $31.41 or more, with the coupon code PIOUS.

Whole Foods: The grocer is discounting all bakery pies and take and bake pizzas by $3.14.

Villa Pizza: Get a Neapolitan cheese pizza for $3.14 with coupon while supplies last.

Your Pie: Pizzas, craft beer pints, and certain combos will cost $3.14 today.

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