What is 7th grade math at your school? He might not be missing much.

My son basically skipped 4th grade math, and then essentially 'skipped' pre-calculus by testing straight into Algebra after 6th grade. This is a normal track for the highest math achievers in my district. The U.S. math curriculum is set up to be spiral and the same subjects are revisited each year at a greater and greater depth. This can be very frustrating to a gifted young math student.