I have learnt a lot from this forum. Someone led me to this in one of my earlier (confused) post.
http://hoagiesgifted.org/hard_won_truths.htm

Now I don't talk abt it at all. Once in awhile, when there is a question on why DS8 is attending higher grade Math, I just reply "They (the teacher/ school) think it's better for him. " and change subject!