Since my kid is one of the oldest here, let me speak from experience and totally screwed perspective:-)
No matter how much you grade skip/accelerate in math, they are still going to top the class if they are PG. My DS was put into Algebra in 5th grade, a class generally reserved for 8/9 graders. He was still the top student. His homework was hell, but he still managed to be the best in that class. This year he is in Algebra II as a 12 year old(late b-day), and the class tempo is so slow, that he is working ahead in the book, on his own. He scored 33 in ACT, his lowest score being Math, in which he is accelerated. He is not accelerated in any other subject.
My point - regular school is not an option for PG kids, whether accelerated or not. I do not know what options there are, that I might not be aware of, but at this point I am sure that my son would be accomodated best having some subjects taught one on one with a tutor.
