We tried Kumon and CTY is way better. At KUMON they wanted DS5 at the time to simply memorize the answers. Off the top of his head he should know 17-9 = 8 etc. I did not like that. I like him to know how to compute it and not memorize the answer even if he counts on his fingers. Doing it fast because of memorization is not really understanding. Plus it is sooooo repetitive. Ther was no way he would do sheets and sheets of the same thing over and over again.