
Ari Essunfeld, a junior at Brattleboro Union High School, recites Pi while calculating various numbers during the first Windham County’s Got Talent held at the Latchis Theatre in January. Photo by Kristopher Radder/Brattleboro Reformer
[B]RATTLEBORO — Ari Essunfeld walked on stage ready to wow the crowd with a big number.
Make that a boundless, breathtaking, mega-digit number.
The 17-year-old Brattleboro Union High School junior stepped into the spotlight of “Windham County’s Got Talent” with a boy-band mane and a microphone. But anyone expecting him to belt out a song was in for a surprise, as he began reciting the mathematical ratio known as pi.
Pi, which is the ratio of the circumference of a circle to its diameter, rounds to 3.14, but in fact goes on forever. Computers have calculated it to more than 1 trillion digits beyond the decimal point. Essunfeld, for his part, will mark Pi Day today, 3.14, by adding to the first 3,140 digits he has learned so far by heart.
“Pi Day can be celebrated either by memorizing pi or eating pie,” he says. “Most people do the latter, unfortunately.”
Vermont math teachers who’ve seen YouTube videos of Essunfeld reciting the first 1,200 digits and showing off his “triple processing” skills have started inviting him to their schools.
The first question they ask, Essunfeld says, is how does he do it?
“For me to memorize four digits, I need to look at them for one second,” Essunfeld says. “When I’m putting longer things together, it takes more time. There’s a limit to how much I can put in my head at once, but I haven’t found a limit to how much I can put in my head over time.”
Which leads to the second question, which is why does he do it?
“I find it interesting and satisfying,” he says, “and it improves my ability to memorize other things.”
Essunfeld recalls hanging out at the Brattleboro Museum and Art Center where his father is director and learning all the exhibit captions.
“When the artists showed up, I was able to talk with them,” he says. “I don’t have my eyes set on a pi-related record, although I know what it is — the unofficial world record is a perfect 100,000 digits. The only structured goal I have for myself is I want to be on the Pi World Ranking List.”
Once verified officially, Essunfeld will rate 13th in the nation and 56th in the world. His family and friends need no external validation of his prowess. They’ve seen it ever since he counted to 1,000 as a toddler.
“One of my first memories,” he says, “is realizing that counting is something you can do without end.”
Essunfeld discovered pi as a sixth-grader at Putney Central School.
“My math teacher would give us the classwork and I’d finish that and then he’d give me the homework and I’d finish that. There was a poster on the back wall with the first 75 digits of pi. I spent my time looking at those numbers, reading them, experiencing them. Soon I realized I knew the first 10.”
Then the next 10. Then all 75.
“Why not double that?” he says he thought. “Why not 150? I built up a bit of an appetite for pi.”
Essunfeld doesn’t consider himself to be a savant or his ability to be singular.
“I don’t think you are born with the ability to excel in math, I think it’s how you develop and are exposed to things,” he says. “I wasn’t introduced to math as a foreign, negative, cold subject. My parents gave me positive feedback and therefore I did more. It just takes practice.”
Nor is math his only interest. He has school and tennis team, band, chorus, jazz workshop, two a cappella groups, his snappyfab.com 3-D printing business and thoughts of college at a place like Caltech, Stanford or MIT.
“I’m not trying to do the corny ‘It’s OK to like math,’” he says. “I’m trying to communicate my enthusiasm and change the way people think. The goal is just to enjoy this.”
In life, he knows that’s what counts.

