Kriston: Back to the OP:
I know I'm coming back in really late in this thread, but wondered if you'd also searched Hoagies for help with ideas for introducing those more complex topics. I've used a lot of the info on Hoagies for finding websites, books and games that address math without actually teaching it.

the physics link has lots of ideas that are math related:

and games are a great way to introduce new thinking:

Take your time to surf around Hoagies. It truly is a goldmine.