As a longtime homeschooler, I have tried many math programs. They all have their strengths, but I find RS M to be intuitive, easy on child and parent, and it gives the child a natural command of mathematics which can easily be integrated into daily life. With other programs, the math appears separate from "life," but with RS, the child learns to think in a mathematical format with items, games and songs that reinforce concepts as well as how math is an integral part of everyday life. The lessons are well-paced, clear in instruction for the most part and enjoyable to complete. The abacus is a wonderful device, and if you haven't tried it, your child will probably love it, even if you are using a different program. The visual combined with the kinetic seems to reinforce all the math facts very promptly and readily. There is some labor involved in putting together some of the cubes etc, but once it is done, you are home free. It would be best to start your child in RS right away. I think it might be harder for an older child to "relearn" some of the ways of thinking about numbers etc, but not impossible. My 10 y-o has done fine, and she is a very hands-on learner. But I see that it is much easier for my younger ones who have only done RS. Great value for the money as well, even if it seems like a lot to pay out right away.