The Exploratorium has celebrated March 13 (3/14) as a way to celebrate Pi (3.14) for a quarter century.
Numerical celebrations on Thursday are being heralded throughout the Bay Area for the mathematical Pi Day with celebrations including math and slices of pie.
Pi Day is celebrated on the 14th day of the third month, which aligns with the first three digits of pi, 3.14, which is the ratio of a circle's circumference to its diameter. Of course, there's a website (PiDay.org). And coincidentally, it's also Albert Einstein's birthday.
People are celebrating in a myriad of ways, including teachers, who want to use the day as a teachable moment.
At Chabot Elementary School in Oakland, the Bay Area Teacher Training Institute is hosting a "pi night," with math lessons and real pie for dessert.
Students at a math class at Mission High School in San Francisco will have a contest to see who can recite the most digits of pi, while another class at Washington High, also in the city, will also have a Pi recitation contest -- all while eating plenty of pie, San Francisco school officials said.
Other student events include composing "piems" which are poems that use words that have the same number of letters as the corresponding digit of pi and calculating the volume of baked pies before eating them.
San Francisco's Exploratorium museum is celebrating 25 years of Pi Day. The museum is moving to Pier 15 in April, and the new location is where a brass plate from the former museum at the Palace of Fine Arts will be ceremoniously placed as a "Pi shrine," according to museum officials.
The California Academy of Sciences will hold "Pi NightLife" as part of a weekly after-hours event at the science museum in Golden Gate Park from 6 p.m. to 10 p.m.
And it's not just students who are partaking in the math-themed fest.
At Mission Pie in San Francisco's Mission District at 2901 Mission St., slices of the bakery's pie will be going for $3.14. The store tweeted: "Come by, get geeky with us."
Pizza pie parlors didn't want to be excluded either. At Patxi's Pizza, with locations in San Francisco, Campbell, Palo Alto, and Lafayette, a lunch special on Thursday includes $3.14 slices.
Bay City News contributed to this report.