Joy of Pi (and brownies)
CHARLEMONT — Years ago, Academy of Charlemont algebra and calculus teacher Stephanie Purington had a “magical teaching moment” while trying to explain the complex principle that a number divided by a fraction (4 divided by ½ ) is equal to multiplying it by the fraction’s reciprocal (4 x 2).
“Imagine you have a pan full of brownies,” Purington told her students. Then she gave examples of how brownies could be divided up into more but smaller servings to feed more people. She was drawing brownie diagrams on a board, when one student grumbled, “It would be so much easier if we had REAL brownies.”
“I happened to have a pan of oatmeal brownies in the car,” said Purington. They had been baked for an event that was canceled. So she brought them out, cut them up into mathematical proportions, then served them up. A star of an idea was born.
“Life is easier with brownies,” says Purington.
Since then, she has duplicated that spontaneous math lesson, stashing away homemade brownies on the day of her reciprocal fraction lesson, until someone suggests real brownies. An element of surprise is a factor in this equation. They have been dubbed “the reciprocal brownies,” and are part of the curriculum at the Academy at Charlemont. They have also brought Purington modest renown this month, in a feature article in Penzeys Spice catalog in honor of “Pi Day,” celebrated on Friday.
“Several years ago, I filled out a Penzeys survey, because I love Penzey spices,” said Purington, who lives in Colrain. Penzeys wrote back, saying they were doing an issue about teachers, and included Purington. In December, they wrote to Purington, to see if they could feature her in a special “Pi” edition of their online publication. Pi Day, a celebration of the number often rounded to 3.14 that derives from the ratio of the circumference of a circle to its diameter, is celebrated on March 14 (3.14), and Purington made it a day of celebration at the Academy about 10 years ago, she said.
The academy’s four math teachers bring enough consumable pies for the whole student body. Penzeys also published Purington’s pie recipe. Purington’s specialty happens to be a chocolate chip cookie pie. “That pie is so great, it makes you want to cry,” says Jenn Rizzi, the mother of a Colrain student.
This year, Pi Day was celebrated a week early, because of the spring break. But students were also treated to lemon pies, strawberry rhubarb, apple and even gluten-free pies.
The pies are served up at 1:59 p.m. on Pi Day, because “159” happen to be the next three digits, after “314” in the pi numeric expression, says Purington.
Purington, who is also the academy’s academic dean, has gotten several “Pi” gifts from her students over the years. One is a cross-stitched embroidery sampler with the first 25 digits of the seemingly infinite number spelled out. Another is a photograph of a Montana mountain range, in which all the snow has melted except for two snow mounds that seemingly spell out “pi.”
In teaching math, Purington tries to find “these little pockets of frivolity, of having fun and being young. I sing with my kids. We have put some math formulas to music. We have a song we do for the quadratic formula in algebra, and the kids can’t wait to learn it.”
“I tell them, when I’m old and all my faculties have left me, to come visit me in the nursing home and sing me that song — because that song will always stay with me,” she said.
“I’m always trying to hook the kids into the material, with something that will always remind them (of a math principle). If there’s a song or a brownie behind it, it makes (the principle) a little stickier.”
“I can’t make everything easier,” she says of math, “but I can make it friendlier.”