Math-U-See is a visual and object based math system, it's actually pretty revolutionary they use color coded blocks to represent math problems and the instructor video uses the same blocks, the student then has a set of blocks that they use to re-visualize the problem. They also start teaching Algebraic concepts early on. We are really happy with it for the K-8th education, as we start to enter high school level math we have been relying on Kahn's more and more. If you want more detail of why we did not choose other programs I can get that info from my wife. She narrowed them down and then I helped choose out of her narrowed selection. I don't know what her filters where for getting down to the smaller selection, I just know that Math-U-See stood out from the 3 we narrowed down to.