I think the trap refers to going fast and reaching Calc too soon. Calc is really a college course, used to be anyway...

It is quite difficult to sidetrack once the kids get into the machine and feel good in it.

Lately I frequently ask myself - why do we learn math? I ask this question with my DS in mind. There are many different answers that I am coming up with but the one that is usually up there on top is to have a deep understanding if its function and application in everyday life. Sadly, one is not going to accomplish this by following a standard curriculum.