After all the ads are run, all the polls are conducted and all the spin is, um, spun, the identity of the next president of the United States comes down to one simple thing: math.

President Obama and Mitt Romney care about one number and one number only: 270. That's the number of electoral votes they need to win and, at the moment, President Obama has more paths to that magic number than does his Republican challenger.

We explain all of that -- and much more -- in our new video laying out the ways that Obama and Romney each get to 270.  It's below.