If you have 5 more years of schooling for him, does that mean he's in 7th grade? Maybe he can be assigned to an 8th grade math class? My difficult child used to shut down because he was bored. When he was in first grade and not reading, his teacher assigned him math word problems on a 4th grade level on the theory that the math concepts would interest him and he would work harder to read them because he wanted to be able to solve them. It worked until the idiot principal found out about it and said no enrichment was allowed for kids who couldn't read! We ultimately wound up changing schools. He's in college now, with credits earned from the Calculus BC test, among others.
Also, every year in our district, they always send a couple of 8th graders up to the HS for math because they are just too advanced for the regular advanced curriculum. My difficult child could have gone but the kid he hated most was going so difficult child refused, which was find with me. He was already one year ahead in math, two wasn't necessary.
The chewing up of the math book is a different issue. He shouldn't be doing that but I wouldn't punish him at home if he's getting ISS. Just be careful about that. My oldest son, who is mildly Aspie, LOVED ISS so much that he would deliberately act out so he'd get it.
Good luck.
