Gaston, N.C. ? “Who you is?”

That’s how a student greeted me years ago in a Miami classroom. I waited to see how the teacher would respond to this insult against grammar, but she did the last thing I expected: She answered the question, as if it had been posed in English.

So it makes an impression on me, standing in a classroom here, when a student says “ain’t” and a teacher promptly and gently corrects him. It is a small difference, but on the basis of many small differences, Gaston College Preparatory and KIPP Pride, a middle and high school side by side in a former peanut field, have carved out one big difference: They work.

According to the state, 83.9 percent of GCP students are performing at or above grade level in math, versus a state average of 66.4. In English, the numbers are 87 percent to 72. KIPP Pride posts similarly impressive stats.

This, by the way, is the latest installment in What Works, my series about programs that are tackling the challenges faced by black kids. GCP and KIPP Pride certainly qualify, and Caleb Dolan, principal of GCP, wants you to know it isn’t because they use selective admission to cull the cream of the crop. As public charter schools, they take students on a first-come basis. Kids come here reading below grade level. Or not reading at all.

So what makes a difference is, well … the differences: a longer school day and year; high expectations as a matter of policy; reintegration of sports, art, band, phys ed and other curricula that have disappeared from other schools; a culture of trust where students store their belongings in open lockers (if you are caught stealing, you must explain yourself to the entire school; Dolan says it’s a potent deterrent); higher teacher pay; a lack of red tape.

“I worked for a good principal,” says Dolan. “Strong disciplinarian, cared about the kids. She couldn’t hire who was in her building. That decision was made in some central office. She couldn’t get rid of the teacher who took naps. Versus, last year I fired my seventh-grade writing teacher because he didn’t get it done in the classroom. There’s too little time to waste with a bad teacher.”

A few years ago Dolan and Tammi Sutton, principal of KIPP Pride, were teachers dangling “quite honestly, at the end of our rope,” frustrated with the failings of ordinary schools. Dolan remembers working hard with one underachieving girl and seeing her blossom into “this dynamic student.”

“Then she’s pregnant by ninth grade.” He takes such failures personally, he says.

So he was primed to listen when he got a call from Mike Feinberg: “You guys want to start a school?” Specifically, a KIPP school.

Feinberg and his partner, Dave Levin, had been where Dolan was – frustrated teachers. Says Levin, “We kept asking ourselves, what more could we do? And one thing led to another.” In 1994, it led to KIPP (the Knowledge Is Power Program), now a network of 57 free charter schools serving 14,000 kids across 17 states and Washington, D.C.

Consider Sherron Lynch, a seventh-grader who thought her mother was “crazy” when she enrolled her in GCP. “I thought it was a regular school, just longer time and mean teachers. But it was so different. Some teachers … only reason they’re teaching is so they can get some money. But at GCP, they care about the students’ education and that really makes a difference.” Lynch’s reading scores have improved by 25 points in the last year.

That speaks eloquently, too.