Good, common core introduces unnecessary complexity into math, reading and science. It’s a really, really stupid idea.
It is actually the final leg of the planned takeover of our children's minds. It is in every subject, however it is best recognized in math and science. When it is in the more social classes it is harder to recognize. But the result is the same to the child, he learns no good moral lessons, nothing to uplift his soul. The goal is to confuse the kids to the point where they will one day fall for any socialist waiting in the wings.
Throughout the school day a child can get to the point where he wants to scratch his eyeballs out. Ever wonder why some kids take a gun to school and start shooting? After a few years of amoral lessons, kids who are secretly troubled, will react. And the result is chaos. The lessons are so well hidden that no one knows, even the teachers.