When I'm going through a practice assessment (particularly when it's math) and I get problems incorrect, I go back and read the explanation and it usually does a really good job of helping me understand; however, I believe it would be even more heavily reinforced if there were an option to do a similar problem(s), but with the values altered slightly. I cannot simply try running through the same problem again since I have just seen the answer so I think this would be really helpful.