Integers Before Subtraction?

The learning consultant to whom I report SpiderGirl's learning activities seemed rather impressed that she was learning about integers in Kindergarten.  It's understandable, I suppose, given that integers usually aren't broached until middle school here.  After all, I haven't told anyone else, lest they think I am "pushing" her.

I offered the concept upon request for something new in math to explore.  We had already introduced simple fractions.  This seemed to be the next logical concept to introduce.  Yet, SpiderGirl hadn't yet mastered subtraction or time or grouping.  What would make me think of such a thing?

Was there method to my madness?

Understanding Large Numbers

Some of our math lessons come at the most unlikely times.  Our car ride to the Canada Day celebrations yesterday was one of those times.

Up until now, I have explained evening rush hour as the time when "everybody" is going home; that's why there are so many cars on the road.  SpiderGirl lately has questioned a couple of times, why are there still cars on the road when it's getting dark?  Why aren't they home?  And yesterday she asked (at 8:00 pm), "Is it still rush hour?"  In response, I asked, "Do you know how many people live in Greater Vancouver?"

Now, I remembered that there are 2 to 3 million people in Greater Vancouver.  (According to the 2006 census, the population of Metro Vancouver is 2.1 million.)  How many is 2 to 3 million?