Not free but reasonable.
http://brighted.funeducation.com/I signed up but haven't used it much. DD8 did like answering some of the science questions.........I had mainly wanted to find some science and social studies questions due to some other tests we are taking in the summer and I didn't know what types of things DD8 was supposed to have to figure out. I wanted to expose her to questions where she may not know the answer. I'm not one for a lot of drilling though so I can't say I will get my money's worth.
