In my case, Horizons Math has worked better than the other systems I have tried in K - 4th grades. Because it breaks lessons into short segments, without focusing for too long on one lesson, the daily assignment has been much easier for my A.D.D. son to deal with effectively. The frequent reviews throughout the workbooks work well for us in the same way. They remind the child of what they have learned, then move them on, which keeps their attention and gives them a sense of accomplishment, quickly. Our normal daily assignment is only 4 pages, getting us through the curriculum in a school year. I have used other systems with my two older children, and have found this working better with my two younger ones. I do recommend Horizons Math.