Oh me? No that's just how I do tips. If they happen to teach
  that in the curriculum, then that's great, although the stuff
  I've seen are like looking at someone ELSE'S math shortcuts that
  I've never seen before smile emoticon

  In my extended answer (this was just part of a longer message I
  wrote elsewhere), I also mentioned that it's related to ratios,
  and that there's 10 10s in 100 and 20 5s in 100 and how I
  visualize it like folding paper.

  If That's what common core is supposed to be, then I hope they
  manage to get that message across. Its a BIG experiment they're
  doing, so I hope they do it right.

  But theory-to-reality leaps are usually chasm-crossing events
  and large scale implementations of things are always full of
  bugs. The bugs affect people's brains so that's why I'm nervous
  about it.