All of the reviews that I read before I bought it said that Horizons Math is an advanced curriculum. When it arrived and I compared their Kindergarten program side by side with the Calvert Kindergarten curriculum that I had used for Jaela and Macey, I discovered that the reviewers were telling the truth! I started Jaela and Macey in Horizons 1 at the beginning of the year, and quickly discovered that in NO way whatsoever had that Kindergarten Math curriculum prepared them for Horizons 1st Grade Math. (OK, to be fair, they DID learn shapes, patterns, how to count to 30, and that there are different kinds of coins, but that was about it.) So, I bought the workbooks for the second half of Kindergarten for them. They have done fine, and once they realized that they are doing "Kindergarten Math -- the same as Anya!", they have worked even harder and done two lessons a day so they can get to the 1st grade stuff. :)
I'll admit it though, even though this program is user-friendly, none of us like Math. Anya says she does, until it is actually time to do it. :) I haven't let on to the kids how I feel about Math, but we do it in the beginning of our day so that we can get it over with and get on to the stuff we really enjoy. But they don't need to know that. :)