(NEW YORK) — Fans of math and pie are celebrating “Pi Day” or March 14, representing the ratio of a circle’s circumference to its diameter, or approximately 3.14159.
National Pi Day became a national holiday after the House of Representatives designated it as such in 2009 with a resolution that “encourages schools and educators to observe the day with appropriate activities that teach students about pi and engage them about the study of mathematics.”
Here are some ways to celebrate Pi Day, pies, and Friday:
In celebration of Pi Day, for three hours, between 1 and 4 p.m. CST, Pizza Hut will give away 140 gift cards ($10 each) when people use the hashtag #PizzaHutPiDay on Twitter.
Pizza chain Sbarro will choose 50 random winners to get a free slice of pizza if they answer this question correctly: What famous scientist shares a birthday with National Pi Day? The chain will announce the details of the contest at 11 a.m. ET on Friday on its Facebook page and will announce the winners at 10 a.m. on Saturday. The chain will also offer a regular daily special of two pies for $20 with any toppings.
Offers will vary by regional Whole Foods Markets, a spokeswoman for Whole Foods told ABC News. Many stores will host activities such as tastings, pie eating contests, pie a la mode, pie walks and warm pie sold out of the rotisserie.
Starbucks isn’t offering a deal on pies, but it’s hard to pass up a free grande (16 oz.) hot brewed coffee. That’s what you get with the purchase of any breakfast sandwich through Friday at participating coffee shops.
Petsi Pies, Massachusetts
Not too far from the Massachusetts Institute of Technology, Harvard University and other venerable bastions of mathematics, Petsi Pies in the Bay State will have pie challenges starting at 1:59 p.m. Why? Pi is 3.14159, Petsipies.com says, adding: For a free Cutie Pie we ask that you verbally recite 10 digits of pi. For a free large pie we ask that you verbally recite 314 digits of pi. For a free Pie per Season gift card (four pies total) we ask that you verbally recite 628 digits of pi.
Again, not a pie, but a worthy Friday deal: Jamba Juice is offering $2 fruit and veggie small smoothies or 12 oz. fresh juice blends, or you can upgrade by paying for a larger size. Participating locations will accept coupons through Sunday.
If salmon sandwiches were “pies of the sea,” then Einstein Bros.’ buy one, get one free salmon sandwich deal would be spot on for Pi Day. Get a Honey Smoked or Nova Lox salmon sandwich after you purchase one, with a coupon.
Copyright 2014 ABC News Radio
Seth Fiegerman, CNN