My son is all over, too. He was whole grade accelerated once (skipped K when first entering school). But then the next year we had to subject accelerate math so he was in 2nd grade with 3rd for math. Then this year while he moved on to 3rd grade he is now privately tutored for individualized math and is just finishing up the 5th grade book.

MrWiggly is very happy right now in the 3rd grade classroom although he complains of everything being too easy. I've asked about subject accelerating for science as the 3rd grade science is really quite limited and slow for him. But he doesn't really want to leave his friends now. Which, by the way, is one reason we strongly advocated to skip K. We know our son and how attached he gets to routine and familiarity! Interestingly enough the whole school team now agrees that he would probably do just fine academically if we skipped him to 4th all the way around. But we aren't doing that right now because MrWiggly says no. So, one year at a time with a little "thinking outside the box" for planning and options. Sometimes flexibility is what is needed most versus finding the "niche" where your child fits.