CYPRESS, Calif. — There are 31 fifth-graders in Mr. Bettencourt’s class at Morris Elementary, but only a handful of chairs.

Since the first week of school, the students have sat — and often bounced — on balance balls to increase their daily movement and improve their academic performance.

“We’re going to be more active and, like Mr. B says, it helps our brain,” said Giovanna Grijalva, 11. “It’s really fun, actually. You can move as much as you want as long as you don’t fall down.”

Doug Bettencourt, 41, started asking parents to purchase balance balls to replace chairs about five years ago.

The inspiration came from a student’s current events report about a class in Illinois that used them.

Bettencourt assigned students to write a persuasive letter to their parents requesting the balls. The practice has carried on ever since, with each new class of students buying a ball at the start of the year.

The balls, in an array of colors, are marked with each student’s name. They are responsible for replacing them if they pop theirs. A former student told Bettencourt that she uses her ball at home.

The students are more active learners, he said. “I encourage restlessness. They’re allowed to move around.”

The students have 120 minutes of P.E. each week, but Bettencourt said students enjoy school more — and learn better — when they have the chance to move throughout their days.

During an afternoon writing assignment, students sat on their balls along tables, sometimes bouncing for a second or two before resuming their essays. Bettencourt has a ball at his desk, too.

“It’s like rebooting yourself,” Bettencourt said. “It gets the oxygen flowing through the body so they’re more alert.”

The students also take short “exercise blast” breaks: They might run in place, do jumping jacks or pull resistance bands. An exercise bike is in a corner for students to use.

Principal Jeannette Lohrman praised Bettencourt’s teaching skills and his emphasis on healthy living. He was named one of Orange County, Calif.’s five 2012 Teachers of the Year.

“He talks to them like they’re his own kids,” Lohrman said. “He reflects back to them his lifestyle.”

Bettencourt runs an optional lunchtime soccer program for third- through sixth-graders. He also talks to his class about making good food choices.

“We as teachers need to be examples,” he said.

Kendall Nichols, 10, said sitting on the ball is good for the core muscles. She said Bettencourt is funny and nice.

“I always thought all the kids liked him because of his personality,” she said. “I didn’t know we got to sit on yoga balls.”