I agree with the PPs - please do raise this with the principal. What the teacher is doing is awful, and in addition, it is really bad teaching.
Just to add my own story: when I was about 10 or 11, we had a teacher who kept a shelf of books in his room for us to read during breaks. The books were all very simple and designed for younger children. A few of us asked him if he could find some more advanced books for us in addition.
A couple of days later, he had a selection of us students read out passages from a book. I was picked, as was one of my friends, then he deliberately picked some of the slowest readers in the class and had them struggle through passages one after another. Then he looked at us all and said 'That is why we have simple books in this classroom.'
I still feel sorry for my classmates. The kicker was, the ones who found reading difficult never even went near the books in the first place, so the whole thing was rather pointless.