Our 7 year old ds is very similar. He is clearly engaged and content at school, though the content is stuff he was challenged by in preschool. His friends outside of school are mainly 10 and 11 year olds in the neighborhood, but he is perfectly happy to spend his days with his age peers in class. When I've observed him and his age peers at school or at birthday parties, I notice that he enjoys their company, but has very few common interests or topics of conversation with kids his own age.
We do our own math curriculum at home, and he is constantly busy working on various projects of his own devising around the house,and I'm pretty satisfied that he's finding interesting problems to solve and pushing his own edge. I homeschooled my older kids, but this one really wants to be in school, and I'm inclined to support him. The school community really attracts him- he's always got a lot to say about the various teachers and students that he interacts with every day and really treasures those relationships.
