Pi Day, celebrated on March 14, is a celebration of pi, the constant that represents the ratio of a circle’s circumference to its diameter. The first three of the infinite digits of pi are 3.14, so March 14 (3/14) was chosen for the annual celebration.

The Berkeley Bakers Baking Club at Berkeley High School plans to celebrate Pi Day by encouraging members to bring homemade pies for the club to enjoy and learn from. “We’re planning to have everyone bake a pie and we’ll try them, and then we’ll rate them (and) give tips on how to improve,” Zolly Corrigan, a BHS junior and assistant president of the club, said. The club aims to be a safe, relaxing environment for students to learn about baking. “We just had a baking contest (where) people could bring whatever: it just had to be baked,” Corrigan said.

Sebastien Minn-Murray, the president of the Berkeley Bakers Baking Club, plans to celebrate Pi Day with his friends. “I have some close friends come over, (and) we all bake pies together,” Minn-Murray said.

FatApples, a restaurant and bakery with locations in both Berkeley and El Cerrito, sees a major increase in pie sales on March 14 in observance of Pi Day. “(We sell) something like 200-250 (pies) between the two stores ... at least tenfold of what we normally sell,” Caryn Carson, a manager at FatApples, said. Among the variety of pies they sell, their olallieberry pie is the most popular on Pi Day and all throughout the year. “An olallieberry is a type of blackberry. It grows in a cold coastal climate, so we get ours from Watsonville down in the Salinas Valley,” Carson said. In addition to selling pies with a pi-shaped cutout on top and making special pi t-shirts for employees, FatApples encourages kids to get excited about math through pies. “We have some fun stuff about how to calculate (area) based on knowing what the diameter of our nine inch pie is,” Carson said. “The other really fun thing about (Pi Day) is that moms and dads and kids come in together talking about math. A lot of times, math is a very angsty conversation between kids and parents because it’s not the most popular subject as far as fun goes. This is one day when there’s a lot of conversation about math between (parents) and kids.”

Peter Seibel, a computer science teacher at BHS, celebrates ‘Tau Erasure day’ instead of Pi Day. Inspired by the *The Tau Manifesto *by Michael Hartl, Seibel believes that the constant tau is superior to the more well known circle constant, pi.

“Tau is the number of radians it takes to go all the way around the circle … The essence of (the Tau Manifesto) is that circles are defined by their radius, not their diameter …When we define a circle, we define it as a center point and a radius and that tells you exactly where a circle is. (Hartl’s) basic point is that the fundamental ratio that we should care about is not between the circumference and diameter, but between the two things that define the circle, which are the circumference and the radius. That just ends up being twice pi,” Seibel said. Even though most students in traditional math classes aren’t taught about tau, Seibel believes it’s valuable to learn. “These days, there’s enough Tauists out there that (if) you want to be culturally educated, you need to at least know what (tau) is,” Seibel said.

On Pi Day, Seibel will be found wearing his tau shirt. “If you want to be slightly contrarian and do things in a better way, even though people have been doing things a different way for millennia, (then) tau is for you,” Seibel said.