22B, we used the same technique-- that worked pretty well up through trigonometry and algebra II material, frankly.
In stats, though, the material was finally challenging enough conceptually that my DD needed regular reinforcement to retain things well. Unfortunately, we probably should have had her there at 10-11yo instead of 14, since she had a lot of years to think that mathematics was a matter of just knowing, intuiting, and/or needing no practice to master. I'm a little concerned about that attitude heading into college.
