Oh, I agree. It just seems like they're missing a couple of years of standard math topics in there somewhere.
On the other hand, as long as the stuff's at an appropriate level for your kid, it doesn't matter whether it's off a bit. Sort of like manufacturer's recommended ages on games-- I often find them to be wildly off, even on the best games.
There's also a more cynical view that occurred to me. Their materials begin at the sixth grade, and they may want to encourage people to stretch a bit if they're on the fence. I wonder if the sixth grade placement test would be a lot harder if they had more elementary material.
