My son has high functioning autism and math has always been where he has the most challenges. I just started using this curriculum this year and can't express enough how pleased I am with this product. There is much review, which has helped with his retention. I also like that there are so many word problems. The other curriculum we were using only used them sparsely. So far, we have had multiple word problems with every assignment and I have noticed that he is doing better in figuring out how to do them independently. I will definitely be using Teaching Textbooks from now on.