So far he's done well using the ALEKS dictionary and the "Explain" button. I have pretaught him a couple of things that I knew he'd need a different explanation for but it gave him something to do at school. I also have covered a few things at home with him completely, then he does the review at school. I think this has been easier because he hasn't reached any truly new material for him yet- it's all building on something he already knows. So if you know long division, it's an easy step to long division with decimals, if that makes sense.

Treecritter- your "Then it slowly builds up" comment concerns me. How slowly? Is there a way to test out of material or do you have to cover each lesson no matter what?