During one session of The Math Circle—a Cambridge-based extracurricular program that aims to teach kids math “the right way”—a 12-year-old girl demanded that Robert Kaplan tell her the answer to a confusing question. The exchange found its way into The Art of the Infinite: The Joys of Mathematics, a recent book which Kaplan, the program’s co-founder, wrote with his wife, Ellen F. Kaplan ’57.

“Our approach is very peculiar,” Robert says. “We don’t tell them anything. We just nudge.”

A mathematical problem is posed at the beginning of each class, and students then lead the discussion wherever they wish. The Kaplans say they insist on a collegial environment above all.

The Math Circle is a fairly recent phenomenon—but people from across the country are already taking note.

“There’s no competition in the Math Circle,” Robert says. “Math is too hard for us to get on one another’s nerves.”

They also try as much as possible to ensure that only students who are truly interested come, as opposed to those prodded by parents.

“The Math Circle doesn’t work when parents force kids to come,” he says.

The Kaplans partially accomplish this objective by scheduling classes at awkward times. Those for younger children meet weekdays around 5:00 p.m., after a long school day.

Adolescents meet early Sunday morning, Robert says with a grin, “the only day of the week they get to sleep late.”

In 1999, Robert published his first book, The Nothing That Is: A Natural History of Zero. The book was a bestseller, praised by The Times of London and The Wall Street Journal and translated into eight languages.

It was then that Robert realized that he had stumbled onto something.

Although he attributes his success to the fact that “there are a lot of loony people to whom zero is important,” he says that “there is a tremendous hunger for certainty.”

“Mathematics offers that, but there’s a cloak around it,” he says.

Similarly, The Art of the Infinite aims to make mathematics more accessible to the general public. One tactic the Kaplans use is to present math along with the history behind it.

“Through history, anecdote, illustration and biography, we make the approach so enticing…that people become engrossed,” Robert says.