I also have reservations about kids taking courses such as Algebra II, Geometry and Pre-Calc before age 11 - while they might get an A in those courses as an eight or nine year old, I also think that they would have a better, deeper understanding if they waited until age 11 or so. I truly think an 11 year old gets more out of rigorous proofs than an eight year old. Just my opinion, as I know others would disagree.
With respect, I think it's not helpful, on this board of all places, to have opinions on what works for "kids", "an eight year old" etc. We of all people should know the damage that can be done by people who don't know our kids pronouncing on what's best for them on the basis of what works for other kids.
FWIW, the way it's currently working for my kid is that the maths he's done for the last year or two hasn't taken him forwards by a year or two in school syllabus terms, and at 10.5 he still has some school maths left to do. (Still, he did Alg 2 a long time ago, and he's more than happy with rigorous proof, thank you very much.) Most of his effort lately has gone into improvement in his ability to solve harder problems, rather than learning more syllabus. That's been right for him. But I have had to decide year by year, and perhaps small differences in him might have led to me deciding differently.
