Also most of the "teachers" have no idea how to teach.
They have been doing this for three generations so the parents of student can not help their children because the "new" unnecessarily complicated way they were taught is not the same as the "new, new, new" unnecessarily complicated way their kids are being taught.
If you want your kid to be able to do arithmetic and at some point higher mathematics you are going to need to either get them a tutor who knows how to teach or learn how to do it yourself. The internet has a bunch of free resources. Use them.
You are right: They have thoroughly screwed up both reading and math with the common core approach. Was implemented by an Oxford Brit and IMO not accidental.