To answer Kriston's question, we haven't tried Aleks. DS did a trial of both Aleks and Larson math several years ago, and he liked Larson better, so we subscribed to that. He did Larson grade 3-6 immediately after finishing EPGY 3/4 and zipped through very quickly.

I have heard many good things about Aleks, and I think it is a solid program.