Westchester County’s vaunted schools make it a desirable destination for New Yorkers fleeing the city in search of better public education for their kids. The county is home to many of the nation’s highest-spending school districts (and some of its highest property taxes to pay for them, at a median $8,422 in 2007). So one might be surprised to discover that Westchester is where Kumon, a back-to-basics private tutoring franchise, launched its first North American base back in 1974—and that today, the county has 14 Kumon centers enrolling 2,200 students.

One of these, in the town of Ossining, sits among a hodgepodge of old storefronts with Spanish names. On a sunny Saturday morning, parents and children streamed in and out of the bland brick office building that Kumon shares with an insurance company. Sitting in the waiting room, John LaMagna of Cortlandt explained why he had brought his son to Kumon. “It helps with the basic fundamentals of reading and math, which kids just don’t learn today,” he said. “Multiplication tables up to 12—like I did as a kid.” While Kumon doesn’t track the effects of its tutoring services on school grades or test scores, Marlene Meyer, owner of the Ossining center, says that she knows it’s working if parents keep coming back—and they do, paying tuition that ranges from $85 to $150 a month per child.

Kumon was founded in 1954 by Toru Kumon, a Japanese high school math teacher who developed study materials for his own struggling son. He believed that kids needed to have a strong foundation in the basics—phonetic awareness and those memorized multiplication tables, for starters—before they could excel at a more advanced level. The curriculum consists of more than 20 defined skill levels for math and reading. New students take a free placement test, get started at a skill level below their current abilities, and move up in small increments. In order for students to advance, they must achieve a perfect score on a test within a set amount of time. The idea is that a child who demonstrates both speed and accuracy shows full mastery of the material. If this sounds like a high bar, that’s the point. A perfect score on a timed test not only demonstrates mastery; it also gives a child the confidence that goes with being an A-plus student.

Glenna Meeks’s twins are enrolled in a Manhattan private school, but she takes them to a Kumon center in the city as well. “Who doesn’t benefit from repetition?” she asks. “Through the repetition you get to see what it is they don’t understand. This is old-school. I was taught that you do something a whole bunch of times and you get it.” She also likes how Kumon charts her children’s progress with the material, measuring how many errors they make and how long it takes to finish an assignment. “They have a mathematical model that tells them whether a child has a good grasp of the material, and they don’t move them ahead until they reach it. In most places, they don’t do anything like that.”

Kumon stresses an old-fashioned aphorism: “Practice makes perfect.” Students must practice their lessons every day by completing worksheets at home. They visit the Kumon center once or twice a week, year-round. The company says that many parents have enrolled their children for the entire curriculum, which starts in preschool and lasts through high school.

Of course, plenty of people would deride Kumon as “rote learning,” but parents seem to disagree, if the program’s rapid growth is any measure: it now teaches more than 4 million students in 46 countries. Some 194,000 of those are in the United States, says Kumon—a doubling of its enrollment since 2001. Kumon’s growth in New York has been particularly impressive, rising over 80 percent since 2001, to 12,485 students last year. Though franchisees own most of its centers, Kumon opened a company-owned center in Harlem in 2005 to reach disadvantaged students in an area where high operating costs made entrepreneurs wary. Within six months, more than 100 students had enrolled. A second Harlem center opened in 2008, as did a center on the Upper West Side. Last year, Kumon opened new centers in Chelsea, the West Village, and Gramercy Park, and it plans more for this year—surely good news for New Yorkers seeking supplements to their public schools.

Paulette Miniter is a writer in New York.