Working Through Practical Problems and Entertaining Strangers: The Benefits of Mental Math

By Rachael Jennings

“My first Geometry class this year revolved around mental math,” says freshman Aggie Macy. “I found it a little odd at first that we were spending so much time learning how to square numbers such as 12,642, but, over time, I learned that it was [more] the process Mr. Weis focuses on and less the answer.”

Math Chair Jonathan Weis


Those who have braved a mathematics class with Math Chair Mr. Jonathan Weis will know the early frustration and eventual exhilaration of mental math. They will know that, like Macy realized, the answers were not as crucial as the process of learning mental math. Those who have visited Dublin during an Open House may even be veterans of his fast-paced mental math competitions, which always cause a flurry of excitement.

“On the first day of class, Mr. Weis taught us how to do simple tricks: how to square numbers near fifty, how to square numbers ending in five, and how to multiply two numbers with an easily squared middle number,” elaborates Charlie Castle. “In class every day, we will have a competition for an extra point on our daily quizzes. It is exhilarating to have the competition which really inspires our bests.”

Indeed, from teaching about on-your-feet thinking and competitive zeal to teaching the larger, longer lesson of creative problem-solving, mental math fosters important skills: not the least of which is celebrating mistakes on the journey of discovery.

“My favorite part about mental math is when I raise my hand, state my answer, get told it's the wrong answer, and then a few seconds later I get the best ‘ah ha!’ moment when I realize what the correct solution is,” says Macy.

The end goal? Mr. Weis calls it “The Mental Math Dream.”

Macy notes that she looks forward to this dream.

She describes that Mr. Weis said “one day you will be walking around a city and someone will ask you what 17 squared is, and then you will promptly reply, “289!’”

“Although this hasn't occurred yet,” says Macy, “I hope it will soon!”

“While Mr. Weis teaches us special tricks for certain problems, it is often fun to come up with your own way to work through a problem,” explains Macy. “By doing this I have become more confident with my math skills.”

Castle agrees, saying that he has found some practical applications for mental math. Overall, as Macy articulates so finely, mental math has helped her become “a sharper thinker.”


Dublin School

Dublin School, Schoolhouse Rd, Dublin, NH, 03444, United States