Just an idea. I think that SAT prac could be more helpful you were able to choose which level that you wanted to practice on. if i could choose if I wanted to level up my skill or decide which level I would  like to practice on I know that it would help me. sometimes to get understanding first I need to practice on level 1 or 2. when pick the right answer by guess, im forced to level up. I want to get more understanding before i go to the next level. that way i will be more successful.

Also in explanations for math, I think that it would be helpful if it told you what kind of what the steps they took and why to simplify an equation or something. I have to figure it out on my own by searching for it on khan academy math. a lot of times I cant find what i looking for. so if the explanation had some kind of link or keys words that I could search on the site to learn more about the steps taken, that would be extreme help. I know I  would gain more understanding instead of having to assume or connect the dots.