Hey Kriston - another thing I was going to ask. Are you still working the more challenging Singapore workbooks? Have you tried giving him the more straight forward one to see how he moves through that? Maybe to introduce a new concept and then move to some harder problems?

I just know my DS is pretty intimidated by the harder workbook without having a really good understanding of the concepts ahead of time. And those workbooks are really great, but I'm thinking they are a lot more challenging problems than the average 3rd grader sees.