ColinsMum,
One of the problems with the "hard problems" approach is that he'll figure out the way to solve the problem type and they won't be hard anymore. It's a great place to start, but someone will need to be constantly ahead of him finding a new "hard type".
That's not as hard as you'd think, for example because there are many different maths competitions with past papers available. They, of course, give assorted problems and try to come up with new problem-shapes often. Alcumus too is good at mixing up question types.
Clay's idea of application sounds wonderful. Perhaps it's time to focus on Physics.
Indeed it is - he's chemistry-mad currently (half way through ALEKS chemistry, and to my astonishment just read Sam Kean's
The Disappearing Spoon with great pleasure*) but he also enjoys physics. These are good ideas, but I don't think they make the problem go away - he'd still be doing things on his own, and would still either be unchallenged or have to deal with challenges without significant teacher input. Well, I suppose that's it: he has to learn to do that!
*I thoroughly recommend this book, btw
