We've done some of each in two different schools - grade skip to 1st in public (CA) with further differentiation in reading and a little in math. Then we were told that was all they would do, no more the next year. We changed schools to a non-profit where DS has been getting accelerated subjects in a 3 year combined classroom. He is about to move up to the next classroom (nominally grades 4-6) and will be the youngest having just turned 8 then. I expect that they will still need to accelerate his math and perhaps a few other subjects even in his first year there, but the school is flexible and promises to do so. Thus, we are finding a combination of skips and accelerations to be the best for us. Once the accelerations really have him in a higher grade in over half his subjects, he gets to move on. The mixed age groupings for classes really help make this successful for us. Good luck!
