One common misconception is that the teachers are to blame for the "new math" being taught. The curriculum being taught is decided by your school board or school superintendent, teachers have very little say in this selection. We finally got rid of the "Discover Math" curriculum in my son's school district, which was a disaster for several years. This is a little off topic but needs to be pointed out.
It isn't the school board, it is egg heads in ivory towers dreaming up better ways to teach. I went through that in Tx as a MSGT in a tech school for 4 years.
"We gotta rewrite the lesson plans, there is this new whiz bang way of teaching". So we did.
9-10 months later:
"We gotta rewrite the lesson plans, there is this new whiz bang way of teaching".
Wash, rinse, repeat. In 4 years we never had a completed package.
Harry K