To some people, Pi Day is about mathematics. To others, it’s an excuse to eat pizza.

Either way, there will be celebrations on Friday, March 14.

Related Articles

Oakland’s hottest new burger joint is an ode to Bay Area hip-hop culture

Alora Social brings coastal Mediterranean flavors to new restaurant in San Ramon

7 awesome Bay Area things to do this weekend

Oakland’s throwing a Persian New Year food event on March 8

Loma Mar: A historic mom-and-pop restaurant becomes a nonprofit

Pi is the ratio of a circle’s circumference to its diameter, named after a Greek letter. It’s a constant number with an infinite number of digits, as explained by the U.S. Census Bureau.

Pi Day falls on March 14 because the first three digits of Pi are 3.14.

NASA’s Jet Propulsion Laboratory in La Cañada Flintridge marks Pi Day online with classroom activities and a Pi Day Challenge.

But at some point, people began associating pi with eating round foods, mostly pizza but sometimes fruit pies.

Pi may be never-ending, but the deals it inspires are short-lived. Most of the promotions described below are only good on March 14.

7-Eleven: Loyalty members can get whole pizzas for $3.14. 7-eleven.com

BJ’s Restaurants & Brewhouse: Dine-in guests can buy one Pizookie and get a second for $3.14. The offer is good for all flavors but can’t be combined with other Pizookie deals. bjsrestaurants.com

Blaze Pizza: Customers can buy one 11-inch pizza and get a second of equal or lesser value for $3.14. The offer is for in-restaurant purchases only. blazepizza.com

Mountain Mike’s Pizza: Customers can get a free mini pizza with the purchase of a 20-ounce bottled beverage. mountainmikespizza.com

Round Table Pizza: Royal Rewards members can get a personal cheese pizza for $3.14 with the purchase of a large or XL pizza on Pi Day. New members must sign up before March 14. roundtablepizza.com