OP, if your DS is enrolled in CTY, you may (or may not) know that he's *only* 10 pts off on his SAT math score to qualify for JHU SET. If you're already considering the Dec SAT for your DS, you might want to have him focus on math prep because, as I understand it, SET offers support/resources for your DS if he qualifies.
Our DS2 (7th grade) is taking the SAT right before he turns 13 just to see if there's any chance he could hit 700 on CR. I really doubt it, but there's no harm in having him take the SAT just to see (aside from the fact that he has to get up early on a Saturday!).
http://cty.jhu.edu/set/services/I'm sorry I can't offer any advice beyond this, but perhaps SET could be a good resource for your DS if he can make 700 on SAT Math before age 13.
Sending positive thoughts your way.
