When I was in 3rd or 4th grade I had a terrible crush on a classmate. Call her Laura. Laura was a very sweet girl, but she was not academically quick. In fact, she was one of the slowest students in the class.
So every time the teacher gave her a hard time - which was freqently enough - it tore my heart.
The teacher would stand her up in the front of the room and ask her the same question over and over again to see if Laura would somehow come up with the right answer. It could be a lesson the teacher just taught, but Laura would stand there like a deer in the headlights, mortified by her own failure to understand, and meekly submit to ridicule. Often enough, the class would be laughing.
And I had to sit there and watch, knowing the correct answer, unable to give it, knowing the teacher was doing Laura no good, feeling sure that I could do a better job of teaching Laura than the teacher was doing.
So that's one very personal reason I like Montessori schools. Because it just wouldn't happen there.
Tormenting the slow
Is no way to go.