Historic Highlights: Math and science geeks love Pi Day but most don’t know what it is

Friday, March 14, is Pi Day, an annual celebration of the mathematical sign pi.

Pi Day has risen from a novelty on the calendar into a global celebration. Math and science lovers revel in it and organize intricate celebrations that only a geek could love. Others simply scratch their heads.

“I’ve heard of it,” shrugged Marty Fullington, 54. “But I have no idea what it is.”

For the uninformed (or, to be truthful, most of us), the day is for pi, the ratio of the circumference (the distance around) of any circle to the diameter of that circle.

That ratio will always equal pi, no matter the size of the circle. The name comes from the 16th letter of the Greek alphabet and is approximately 3.1415926.

Depending on how old you are, pi is studied by most Americans in high school geometry or science. Obviously, some take that to heart, particularly math whizzes.

“Pi Day is fun,” said Darrin Deneve, a mathematics teacher at Carlinville High School in central Illinois. “Here, we don’t go as far as some other math enthusiasts do. But we do celebrate.”

The day originated in 1988 at the Exploratorium, a science museum in San Francisco, by Larry Shaw, a physicist on staff. Shaw created the day to celebrate not only the number, but mathematics overall.

The day itself is a wry takeoff on the number. Pi Day is March 14, or 3-14 on the calendar – corresponding to the first three significant figures of Pi, 3.14.

Shaw’s idea seemed like a novelty at the time. Since then, Pi Day has grown into a global event, as math fiends worldwide mark the day in a variety of ways.

The site weareteachers.com offers no less than 42 Pi Day activities that are described as “mathtastic.” They include paper chains, counting exercises on circular objects, memorization of the digits of pi, and art projects.

Pi Day may have grown with the emphasis on STEM (Science, Technology, Engineering and Mathematics), which has received increasing focus in American education. Some also take the day to honor Albert Einstein, who was born on March 14 in 1879.

Pi Day has even become an official holiday, thanks to Congress. In 2009, the House of Representatives passed a non-binding resolution to designate March 14 as National Pi Day.

The next year, Google got into the act with a Google Doodle on the day, which is not just for kids, at least according to the math and science people. Teachers aren’t the only ones to join in; college students, STEM professionals and enthusiasts among the public also love the day.

At the Massachusetts Institute of Technology, one of the few places where everyone actually knows what pi is, responses to application letters are often sent to arrive exactly on Pi Day. MIT also works pi into one of its fight songs, with such math-oriented lyrics as “Cosine, tangent, secant, sine / 3.14159.”

Pi Day has become a favorite of American mainstream media, who routinely report on the holiday each year. But the day is clearly celebrated only in pockets, as the hype does not seem to resonate with the masses.

“I don’t really care about it,” said Hannah Crawford, 28. “I remember it from school because we always did something about it. I thought it was a really, really stupid day.”

“I guess it’s good that someone cares about it, and people want to celebrate something,” said Fullington. “But I think the whole thing is kind of corny.”

For all of the love coming from the niche of math lovers, Pi Day in 2025 won’t have the same meaning as in 2015, featuring a special moment only a math fiend could love.

That was 9:26 a.m. on that day, which was 3-14-15 on the calendar. Put them all together, and it corresponded to the first seven digits of pi – 3.1415926. Because of that, the holiday in 2015 was dubbed Super Pi Day.

“I celebrated the moment on radio, the Sports Saturday show on WSMI,” laughed Deneve, who has won 334 career games in 19 seasons as a high school girls’ basketball coach at Carlinville.

Deneve, who is known in the community for his love of all things mathematical, also presented a word game based on this phrase: “How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics.”

“If you count the number of letters in each word, you get the first 15 digits of pi,” said Deneve. “Of course, for a more G-rated version, one can change the word ‘alcoholic’ to ‘chocolate.’”

That’s far less than the actual number of digits in pi. In 2022, a team of Swiss researchers calculated that pi consists of over 62.8 trillion digits.

That’s enough to make anyone’s head spin. Many prefer to honor the day in smaller terms, with a different kind of pie – the other kind, with the extra letter. Many Pi Day activities include pie, a tasty way to celebrate the day in many circles.

“We got pie for it. That was a bonus,” laughed Crawford. “So I guess something good came out of it.”

• Tom Emery is a freelance writer and historical researcher from Carlinville, Illinois. He may be reached at 217-710-8392 or ilcivilwar@yahoo.com.