Are grades really accurate?

I used to always get sent to the office because of my teacher accusing me that I was cheating, she would say that if she couldn't do it in her head, then neither could I, fucking communist whore who doesn't understand algebra isn't my problem.

But to the subject, Grades in grade school are not accurate, maybe to Work Ethic as Voll said, but actual mental ability are judged on statewide tests. Not until you get to college will you be graded on your intellegence (unless you play a sport for the school, then your set )