Apparently, my 10 year-old son and one of his buddies at school broke a chair in the classroom. The details are unclear, but the end result is that a chair is broken. (Jokes about my son being fat enough to break a chair will be great. He's 10 years-old and weighs 45 pounds. That's a gain of 3 pounds from the end of football season.)
My son told me that the teacher asked each of them to bring her $3 for the chair.

We've had no interaction from the teacher about it. There was no note or email or phone call. The teacher apparently expects my son to show up with $3 in cash and hand it to her. $3 isn't a big deal, but does it seem strange that the teacher works directly with the 4th grade student to collect money for something like that?
My son is stressed out about it so I was tempted to just give him $3, but I also want to hear an explanation from the teacher. Is that an unreasonable expectation?