Art of Problem Solving covers algebra and up and then some. There are online courses and great books. It's great stuff and there are free programs at the site (alcumus).
Ha, thank you! I had never heard of Alcumus. I'd looked at AoPS generally and in fact have just bought a couple of the books (Intro to Geometry and Intro to Algebra - but not Intro to Counting and Probability which is the only one currently available in Alcumus, so that may be on my shopping list soon...). I had looked at the online courses, but they won't work for DS because of the timezone (even if they'd work with DS's current keyboarding skills, which I'm not sure about). However, looking again just now, I see that they plan some "homeschool and Europe"-friendly timings for courses in the autumn, which is great news. Maybe DS will learn to type over the summer, lol.
