WILLIAMSTOWN, Mass. — On any other day, Pine Cobble School students endlessly and willfully dropping pens and markers on the floor might be sent to the office of the head of school.

But this was Pi Day, and Head of School Susannah Wells was right alongside them dropping pens and markers too.

Pi Day is celebrated at schools nationwide to promote math literacy. It is held on March 14, or 3/14, when the calendar mimics the value of pi (about 3.14), a constant named for the 16th letter of the Greek alphabet and representing the ratio of a circle's diameter to its circumference.

On this day, Pine Cobble students were simulating Buffon's Needle, an experiment developed by an 18th century French mathematician. The more times Buffon dropped a needle on a sheet of lined paper, the greater the chance the probability of the needle crossing the line approximated the value of pi.

At Pine Cobble Thursday, the needles were replaced by pens, and standing in for the lined paper was a sheet of plywood segmented by masking tape.

After three rounds of experimentation — and hundreds of drops by students from varying grades (and Wells) — the value was 3.08.

"We're getting closer," remarked fourth-grade teacher Giom, who led the experiment, one of five stations of fun math activities through which the students rotated Thursday morning.

Giom (no first name) was one of four faculty members coordinating the Pi Day festivities, an all-day event at the school that was revived last year after a hiatus of several years, she explained.

"Pi Day is all about getting the kids excited about math," she said.

Although the actual concept of pi is not introduced until the fifth grade, children in grades 1 through 4 enjoyed concrete activities like replicating Buffon's experiment, drawing tesselated pictures a la M.C. Escher, creating art in the style of Sol Lewitt, doing math puzzles or mazes and even, yes, calculating the value of pi with by drawing a circle and measuring its circumference and diameter.

All of the activities on Pi Day involved pairing up classes from the lower grades with classes from the upper grades. For example, the second- and seventh-graders joined forces for a round of "needle" dropping.

That kind of interaction among grades is not unique to Pi Day at the private day school for pre-kindergarten through ninth grade.

"It's a big part of what we do: The older kids mentoring the younger kids," Giom said.

"It's a common event," said Upper School math teacher Jerry Bope, an 11-year veteran of the Pine Cobble faculty.

"At lunch every day, each table has a member of the faculty, a ninth-grader, an eighth-grader, a seventh-grader, right on down the line. It's a daily event. They're used to it."

In addition to the morning's activities, puzzles and experiments, Thursday's Pi Day featured an all-school project to produce a wall mural in the style of Lewitt, a recitation contest to see which student could memorize the value of pi out to the most number of places (the constant is an irrational number, extending infinitely after the decimal point) and a viewing of the 1959 Disney cartoon "Donald Duck in Mathmagicland."

But that was not all the fun to be had.

"Of course, we'll also eat some pie," Bope said.