Coolmath.com- middle and high school math

I just found this wonderful resource for Algebra and pre-algebra. http://www.coolmath.com/index.html

It's very user-friendly, has simple, easy to understand explanations, and has a complete online math textbook for Algebra I and II (plus a "work in progress" Pre-Algebra, and stuff for pre-Calculus and I think maybe also Calculus, but I didn't look at those sections closely since we don't need them yet.)

Now I don't need to worry about purchasing any math textbooks for DD2 if she continues homeschooling long-term. It's free to use because of the banner ads, so when you use the site directly they're still making money (so you don't need to pay directly to support the site, or worry that they can't afford to keep the site open.)

The best part about this was that the girls could study math independently. I had both computers on, and they worked on different levels of math simultaneously, while I stayed nearby to answer occasional questions (and read a novel.) When we were working with textbooks, I could only teach one child at a time, which limited the amount we could do at once (the other child would get bored waiting for her turn, or she'd be "out of the math mode" by the time her sister was done and it was her turn again, etc.)