Get him started on Aleks
www.aleks.com
It will give him a diagnostic test and is self paced, so excellent for a classroom situation.
Some private history - DS attended private school since pre-K. Was always very anxious, worried, who knows what about it.
Private school was testing kids yearly beginning in 2nd grade. DS was always 99%. Fast forwad to 4th grade. Gets " normal" home room teacher who finally tells us that our son is way above other kids and we should try to do more for him.
We have decided to move him to a charter school that promised to teach him to his ability. On his math diagnostic test he "tested out of high school" ( I do not know what test it was).
So the school has put him in Algebra I since he has never taken any advanced math courses nor has he been taught by us at home.
Looking back, it was a mistake. I would reccomend pre-Algebra course for all young math whizards. If taught properly, it gives the review of all the important math needed for Algebra I. DS did Ok, but it was stressful for the first semester. Here was a child who never did any operations on fractions (how the heck did he score out of HS???), and homework was a HUGE time consuming project every evening! He did manage to finish that class as a top student anyway, but the beginnings were hard. He is now in pre-calc as an 8th grader and will run out of math courses at HS in a year. Not a bright idea to look at.
Have a look at
http://www.artofproblemsolving.com/Resources/AoPS_R_A_Calculus.php