Great experiene!
Very affordable, the lessons are very well done and surprisingly engaging. Took Calculus 1 course, here are some things I encountered: A few lessons are a tiny bit out of order, but nothing bad enough to prevent learning. This was the only slight drawback, which is surprising considering the price, and other than the few out-of-order lessons, everything was very well put together. The lessons had a good mix of entertainment and learning.