I have just had my attention drawn to these two wonderfully simple sites providing some great video tutoring in maths and science, among other topics, either as a supplement for studying school topics, or as a resource for home schoolers. Brightstorm and Khan Academy. Aimed at junior high school/high school, but obviously really great for gifted students who just want more!
Or in Bill Gates’ case, he just wanted to help his son with some homework and needed some revision too!! Sounds like me!
In the Kahn Academy’s case, just choose as much or as little as you like from over 1800 short videos with written instructions to follow on your screen as well.