Thanks again. I was looking at the "Well Trained Mind" forum for ideas-seems that the EPGY program is popular on the accelerated learner board. I think we may try it over the summer.
We're continuing with DS's private school- he could use some math acceleration, but likes the Montessori curriculum. It also makes me comfortable that he is reviewing concepts and filling in gaps. Next year, the grade is transitioning into Singapore math.

1111- my ds7's style for learning new material is to refuse to listen to advance instruction, struggle through, make a mistake, scream and run to his room. Rinse and repeat until he has achieved mastery through the school of trial and error. I sincerely hope it's a maturity thing.