I was good at math, but my mother ran a Kumon center as her small business, and I had to do Kumon so that she could use me as an example. I felt sorry for those kids. In the end, I think the repetition method helped a lot of the students. But the style is so different from the American educational system that, from the perspective of someone who did fine in public school, the Kumon method just felt.. dirty. Like corporal punishment.