IQ is a snapshot of a single day. If you've read Ruf's 'Loosing our Minds/5 Levels of giftedness' that might round out the picture a bit.
I think that his science is impressive, and you may want to do a portfolio, but I wouldn't stress the Math, as by age would be actually be a 3rd grader in some states, so doing 5th grade is definitly MG, but not a sign of PG.
Have him dictate some book reports of some of his harder books, and video him talking about his HS Science, and I think you have a shot at DYS.
Best Wishes,
Grinity
