I'm not sure who to side with in that story you've shared, because I can relate a little bit with the teacher especially if these children are really incorrigible. I remember bringing my daughter to school and noticing this boy in her class who is very naughty and is always starting disputes with others and hurting his classmates. The teacher however doesn't mind to correct his attitude or get his attention, and I remember thinking to myself that if only I were the teacher I would have definitely done something about it already.

I guess there are just some over-lenient teachers, and there are some who decide to do something about the situation. If she feels that the only way to get their attention is to give them low grades, then there's a possibility that she's right and probably this was her last resort. If they don't listen after being warned that their grades will suffer, then perhaps they deserve the consequence.

Originally Posted by SageMother

. Had the student been instructed to remain quiet, but talked anyway? Is this repeated misbehavior that had stretched beyond the final incident? .

No, the student was a quite one generally and in that situation he just responded to the other who have asked him something .
However, even if it was the case like you said ,the school rules for discipling disturbing kids were very different from what teacher did.
She should have announced the child's formmaster ,who should have announced his parents and if the child continued to misbehave in school , he was supposed to have a lower mark on "behavior", not on math .

Also, the teacher was not first time acting like that , she used to do that to many other students before and the school principal knew about that .