Someone recently sent me a link to the Khan Academy’s site. This person has over 800 videos on YouTube teaching various math courses. The videos aren’t too long, but the amount of them is quite impressive. If your child is struggling with a concept, see if there isn’t something on this page they can review to get up to speed.
Not only does he cover tons of math subjects, he also has a lot on finance including some analysis on the Geithner and Paulson plans.