I think grade acceleration is a very individual decision, and it really depends on what the school and you can do to ensure the child is learning, growing and happy. Some kids will do great with acceleration, and others may be happier with their age peers socially. When our DS was in K, he could have been accelerated based on academics, but on social and motor skills, he wasn't ready. If anything, I wish he'd skipped grade one, but we waited because we didn't really know better and met resistance. DD could accelerate, but she doesn't want to, and we have found a happy medium. In second grade, she had a really special teacher, who encouraged her strengths in math through a small-group cluster, and that made up for a lot. Now we're trying to figure out what to do for next year.
When we accelerated DS, he jumped right in and was right at top, because he tested very high on one-grade-above material and also compared to two-grades ahead. We did no outside fill-in, and if there was anything missing, he's picked it up along the way.
