March 14 is Pi Day, a day to celebrate the mathematical constant 3.14159265 (and on and on and on). Pi is the symbol used to represent the ratio of a circle's circumference to its diameter.
The date -- 3/14 -- is also the day that restaurant chains offer up deals on pies and pizzas. Whether you're celebrating for the mathematical constant, a slice of pepperoni pizza or both, take advantage of these deals on Tuesday, March 14.
For more, here's a list of restaurants that will give you free food on your birthday.
Blaze
Visit Blaze on Pi Day and enjoy any Blaze 11-inch pizza for $3.14 when you download the Blaze App and join Blaze Rewards.
Casey's
Visit Casey's on Pi Day and take $3.14 off any large pizza.
Cheddar's Scratch Kitchen
Grab a Cheddar's Scratch Kitchen chicken pot pie, a side salad and a honey butter croissant on Pi Day starting at $11.
Cicis Pizza
If you dine in at Cicis Pizza on Pi Day you can get $3.14 off Cicis' adult buffet, plus a kids' combo for $3.14. For people ordering takeout on Pi Day, you can take $3.14 off a large one-topping pizza when you use the code PIDAY at checkout.
Domino's
Customers can order two or more items from Domino's mix and match menu for $7 each on Pi Day when they order carryout or delivery. They can also grab a one-topping pizza, a Dips & Twists combos or eight-piece wings for $8 each when customers carryout.
Papa Gino's
Get a small cheese pizza from Papa Gino's for $3.14 when you purchase any large or extra large pizza on Pi Day. To claim this offer, use code 9220 at checkout.
Papa Johns
Papa Johns is offering its Papa Rewards members a Pi Day BOGO. Members can buy one large one-topping pizza at regular menu price and get a second large one-topping pizza for $3.14.
Papa Murphys
If you purchase one of Papa Murphy's Tuesday specials online on Pi Day, you will receive a coupon code for 31.4% off your next order. The coupon is valid starting March 15 through March 28.
Pieology
Pieology's Pie Life Rewards Members can receive 3.14 times the rewards points when they place an order on Pi Day.
Round Table's personal cheese pizza.
Round Table PizzaRound Table Pizza
Round Table Pizza members can visit Round Table Pizza on Pi Day and receive a personal cheese pizza for only $3.14.
Sbarro
Get free delivery on your Sbarro order on Pi Day.
Schlotzskys
Rewards members can buy one Schlotzsky's pizza and get the other free on Pi Day when they order online, in-store or through its rewards app.
Uno Pizzeria and Grill
Dine in or take out a thin crust cheese or pepperoni pizza at Uno Pizzeria and Grill for $3.14 on Pi Day.