|Photo courtesy of Americans Against Common Core. Used w/ permission.|
I understand that sometimes we want to give children "number sense" or show them different ways to solve a problem. There's nothing wrong with occasionally showing children this sort of thinking once they have a solid understanding of how to do it the standard way. Certainly what I often would do in cases like these is take the 200 away right off. I'm left with 368 - 93, which I would either line up old-school style and solve OR I'd take 100 away and add seven. Whatever I felt was easiest at the time.
But I think if I were shown this backward/ shortcut way of solving the problem at the same time I were learning my standard algorithms, I'd be very confused. And that's just what many schools are doing now. I know that works for some people, but I don't think we're helping a large number of children with this teaching method.
Worse still, schoolchildren often bring home entire packets of homework which must be done as above and/or the answer "explained" in a sentence. Often schools hold entire "how to do Common Core math" parent nights to explain to the parents how to help their children with schoolwork at home.
It just seems like a lot of energy to expend on something that will be understood more naturally later.
Caveat: this sort of convoluted math has been in schools since Patrick was little, and he'll be 23 this year. So the example above is not just a "Common Core" math problem, but a problem we should all have with the "new math" that is de rigueur in all schools under the current system. Still... yuck.