I was in that situation when I was his age.
He doesn't know why he's doing the work. It's tedious and boring and there is no benefit from doing it. There is the illusion of the prospect of
maybe high grades, but the time required for work and rewards for that work is totally unbalanced.
Imagine if someone asked you to do 4 hours worth of work every week for 10 weeks, then at the end of it you get a piece of paper with a number or letter on it. It doesn't make sense. In his world the work really doesn't
need to be done and even the punishment for not doing the work isn't as bad as the work he has to do.
Find out what he wants to do and see if you can arrange for the teacher to give him homework in that field. Or make up homework for him yourself that he finds interesting and hand that in to the teacher instead. As you say, he's smart and finding a way to get him to do the mundane homework might dampen that. Right now it sounds like he's creative and thinks for himself. He's already learnt the subject matter and doesn't see the need to do homework. Work with that. Self discipline and industry for doing the work required are really good skills, but only if the work is actually
required.
Given all this, I think the best solutions would be:
- Find out why he doesn't do homework and see if there's a deeper issue that needs to be addressed: ie- the work isn't challenging.
- Make homework for him that's challenging, fun and will make him think. Use some of his natural creativity.
- See his teacher about setting up a homework plan that he will enjoy.
They might be impractical, but they might have sparked your own ideas. You know your son better than me after all.