Joys- I read your earlier post where the teacher mentions that you should consider red-shirting, and you are now talking about grade skipping. So, to me, I am hearing that you have a child who is advancing in different areas at different speeds. That's pretty typical of these kids.
One solution that has worked well for many folks is subject acceleration, where the child can jump ahead in, say, math but stay in his own grade for social reasons. Heck, you could even red-shirt him but accelerate him in math two years.
This is all much easier said than done, but something to consider.
The thing with elementary school math is that it often spirals around and around and for these kids it can seem endlessly repetitive.
