For many years of my teaching career, I taught the General Math classes. I taught these students all day. Most of them were just a few points above qualifying for special education programs. They were not well-motivated, although I could get most of them to do most of their work most of the time. But their skills were low. They would not have been considered proficient on any standardized test.
I hate to think that my teaching career and my paycheck would have been dependent on the scores of these students. I'm afraid I would have been very, very poor and probably looking for another job.