I learned about these disks while at Texas A&M University. They use these for the freshman there and have found them very helpful. There are a couple versions: one for Intro Chem (high school level) and one for General Chem (basic college level). The disks allow you to do problems over and over and they give feedback all along, letting you know what you did wrong and allow you to fix it. There are some animations, too, which helps with chemistry. Scores are saved and the highest score per section is retained. This is perhaps the BEST homework and tutorial disk I have ever seen for chemistry. It's not too flashy so it's easy to learn and do. I highly recommend.