The humanities courses might be fine, but the math didn't seem very advanced (and my kids are not math types). I would try to find someone who has attended to learn more. I would also look into
http://www.curiousjanecamp.com/ and check into the Curious Jane or Blue Tree programs (held at the same location as SIG).
do you know of any other camps in the area for younger kids?
I've been looking and only JUST came across the SIG camps. This curious jane looks right up my daughter's alley!
Googling 'gifted camps on the main line or philadelphia' gets me no where though. I don't know where to look.
