The thing that takes getting used to with AoPS is that there are almost no repeat questions. Virtually every. single. question. introduces a twist, so it's well worth doing all of them. Which can take a really long time, but is worth every minute.
We did pre-Algebra the first time in about 6 weeks (with only grade 4 math at that point) - doing just enough out of the textbook to get the basics and complete all the Alcumus questions. Then we did Algebra 1 online. DS had the concepts, and did OK in Algebra, but we really wanted to do all the questions on this course, and it was going WAY too fast for us, with our limited prep and limited time (after-schooling). Now, we've gone back and are slowly working our way back through the whole pre-Algebra book, skipping no questions this time, and realizing the book gets a lot more complex than Alcumus.
And this time, DS is loving the math, and really, really understanding how to use these very simple concepts to solve some pretty tricky problems. Now that I've learned my lesson, I've no doubt we'll go back and re-do a big chunk of Algebra as well, cuz this time I won't rush him, and it will actually be fun.
