For many elementary school students, math can be tedious and boring. But in Mr. Ferguson's fifth grade class, even a lesson in complex fractions is a loud, raucous affair.
The all-boys class is often on its feet and huddled together. At times the students walk around the classroom to burn off nervous energy. And the boys are encouraged to blurt out answers rather than wait to be called on.
A former firefighter, Jeff Ferguson isn't afraid to get in his students' faces.
"I speak loudly to them," Ferguson said. "And if I were to talk to a girl with the same volume, they might think that I'm yelling at them, but I'm really not."
Ferguson teaches at the Dr. Walter Cunningham School for Excellence in Waterloo, which began offering single-sex classes for interested students five years ago.
"[Students] were not achieving the way we wanted them to achieve, and at that point we knew we had to think outside of the box," school principal Elizabeth Crowley said.
The classes have helped several students, especially boys, lift their grades and test scores, Crowley said. And she said there are now fewer disciplinary problems.
Charvis Bentley, 11, used to get Ds in co-ed classes before his mother enrolled him in Ferguson's class two years ago. He's now getting Bs.
"I would always get in trouble because the girls would always say something to me, and I wanted their attention," Charvis said.
Across the hall, the girls in Ms. Schmidt's second-grade class start their day by sitting in a circle, sharing their feelings, and affirming each other.
"You're a very smart girl," we heard one girl tell her best friend in the circle. "Don't hide your beautiful face."
It's a scene that might make a boy cringe, but usually there's not a Y chromosome in the room. The all-girl class is noticeably polite. They raise their hands, listen intently, and rarely talk over each other.
"It's so important that they have that time to think through the process and be able to verbalize what they want to say," teacher Amy Schmidt said.
There's no hard evidence that single-sex classrooms lead to higher achievement, and the nation's teachers' unions neither endorse nor oppose the concept.
Private schools have traditionally been single-gender, but only recently has the trend grown among public schools, which have a checkered past when it comes to separate-but-equal education.
Some critics think single-sex classes leave kids ill-prepared for a co-ed world.
"Frankly, I think that it's a little difficult for a boy who has never had to compete with a girl on anything, even an algebra test, to go out into the world of work and be supervised by a female," said Kim Gandy, president of the National Organization for Women.
But the boys at Cunningham Elementary disagree and say Ferguson's lessons go beyond academics.
"They teach us how to be gentlemen, treat others with respect," said fifth grader Davion Givens.
And the students enrolled in the single-gender classes aren't separated from the opposite sex all day. Lunch, recess, and fieldtrips are all co-ed.
"They're ready for a co-ed world," said Ferguson, who then offered an analogy. "If you're going to build a ship, you build it on dry land, and then when it's ready, that's when you put it in the water. The foundation is there. They're ready."