[exDemMom]

Yes, that also works. It does not matter much how you break it down, as long as you understand the fundamental process.

[morphing libertarian]

I find people develop their own systems. I used to sit in meetings and add columns of numbers in my head as fast as someone wrote them down.

When asked how I did it I merely said, catholic school.

The common core example is too convoluted. It seems to turn simple addition into algebra.