I thought everyone did this, I don't think anyone in that classroom was actually learning anything about the contents of the text, all anyone could think about is "don't fuck up saying words out loud"
I was the kid that would whisper the words that other kids were struggling reading so they would get it right while also counting ahead to practice my paragraph. Then I would get pissed because the teacher would say to keep reading when it got to me so I had to read more out loud than the other kids did.