Here's another useful list, same comments.
http://www.pbs.org/parents/childdevelopmenttracker/index.htmlA nice thing about this one is that it distinguishes things that "almost all" children will be able to do at a given age from things that "most", "some" or "a few" children will be able to do. Watching other children convinces me that their maths descriptions are really on the low side, though; e.g., his (unselective) school is routinely expecting all children to do things that are beyond what this checklist suggests would be ND. So don't get too excited ;-)
