I do it, too, and I was taught to do it when I was young. The difference is that I was taught to do it after I had a solid foundation in basic arithmetic.
Common core does not mandate the content of textbooks. The textbooks seem to emphasize shortcuts in order to get at alternative explanations for the principles. They de-emphasize the foundation in order to solve the problem. That’s great for people who understand math. It confuses people who don’t.
It also doesn’t help that a friend of mine taught at a university and observed, “Education majors are the stupidest people at the school, including the janitors.”
He showed me examples. :)
Well put.
and about this: “Education majors are the stupidest people at the school, including the janitors.”...
I had a 5th grade teacher who described gravity as a shallow band of invisible material covering the Earth, and she believed wheels rolled because their shape enable them to move through the gravity material the best.
And the third grade class next to mine had a coke snorting addict for a teacher who would pass out at her desk :)
So some of these teachers are not rocket scientists.