My daughter (whose strongest subject and passion is NOT math) skipped 6th, did no work over that summer, then did well enough in 7th to move up to coordinate algebra which actually goes on HS transcript. The summer before algebra she filled in some gaps with a boy from her grade who is a math whiz, I think she met with him 4 or 5 times. There were lots of tears when she didn't understand immediately. But today she was one of a few kids (in a large school with a high percentage of gifted kids and lots of great math students) to get a math award at the 8th grade ceremony. So, honestly--I bet he will do just fine. I know your son would be doing algebra a year earlier, but anecdotally it seems to me that these kids rise to the challenge. And it certainly helped my daughter to practice some persistance. Good luck!