My daughter is the same. She's always asking to "do school". I'm trying not to push her so I'll ask her what she wants to do. She'll usually tell me reading eggs, coloring, art, or reading. At his age just follow his ques and you can't go wrong. It's not like your pushing him. I know that classical hs doesn't encourage academics early, but I wouldn't hold him back. You probably wouldn't want anything text book, but lots of fun hands on learning won't hurt him. There is also lots of really fun and engaging computer learning game online that are either free or really inexpensive. My 4 year old loves playing games like reading eggs, ABCya, and anything on PBS.org. Also, try some cut and paste activities for him to learn some new skills.