Thanks all for the suggestions. I'll look into the AoPS. I personally disliked geometry and trig, and was more interested in (and better at) algebra and calculus, though I maxed out at third semester calc in college and couldn't quite manage sequence and series so I stopped math. Ironically I had to teach myself some linear algebra in order to do some statistics in grad school and wondered why I hadn't encountered those topics sooner. Anyway - i mostly want him to be challenged generally -- even if it's not in math, and my guess is that his humanities courses will provide some challenge simply because they force him to write complete sentences.
What was the challenging aspect of human geography? Content or analysis?
