Last week Marilyn Just emailed me with a couple of suggestions to add to my list of mathematics resources. One of the suggestions that jumped out at me was the Art of Problem Solving. The Art of Problem Solving offers a variety of tutorial resources for students. Some of the resources are free and some are not. The highlight of the free resources is a catalog of more than three hundred short instructional videos like the one embedded below.
The bulk of the videos are designed for pre-algebra and algebra lessons.