FYI for all, this document lays out Professor Wu's ideas about how to teach fractions. I'm about to go over the third grade stuff with my DD, having just written up 6 pages of lessons. To me the differences between what see coming home from school and his stuff are subtle, yet profound. Wu's stuff builds a foundation of knowledge about how everything fits together, whereas the stuff I've seen from my kids' schools doesn't. The kids can manipulate stuff very well, but they aren't shown all (or most, really) of the connections.

Quantum2003 and cricket3, did you and/or your kids learn Wu's ideas?