Thanks so much for your responses so far. I do think screen time can easily get out of hand. I haven't given him the ipad lately because he keeps crashing it. But even before that I was going back and forth about whether the computer provides healthy learning opportunities or unhealthy addiction or both.

Marnie, thank you for the suggestions. Your comment that "lazy days don't work very well here", struck home to me. I think I got used to him being very independent as a baby and toddler. Right now he isn't independently engaged in some intense learning pursuit and maybe that's okay. Maybe I just need to keep on preparing ahead to provide more structured activities, even if they don't entirely capture his interest. I guess I just thought all kids liked imaginative play... That's the sort of thing that comes more naturally to me than preparing activities or answering questions.