I really loved taking the Prealgebra courses! They were so insightful and helped me understand and think in ways that I normally don't. I like that when I ask for help with, say, a free-response question, the moderators/instructors/teachers don't just tell me what the answer is; they lead me to figure out the answer. A friend of mine told me about the course because she takes it too. I'm really glad she did, because it helps me understand, not just blindly accept, things that I didn't get before. Thank you, AoPS!