Andy wrote:
Good teachers should be able to cope with children of different abilities within the same class - offering more varied work for kids who are more able. It's the teacher that's at fault in your wife's case, I think, not your mother-in-law!
At fault perhaps, but I don't think it's uncommon. Ultimately if you have a class of mixed abilities and a limited amount of time to prepare your teaching you're always going to shoot towards the low end of the middle of your ability range, I think - on grounds that those who are more able will not take up your time in finding it dull, but those who are less able will demand more of your time and attention. Even pitching right in the middle of the ability range would seem to me to be dangerous in terms of the amount of time you'll need versus what you'll have.
I was in much the same position as your son, Mikey - one of Mum's favourite stories is the time that I (at six years old) told the teacher that no, I wouldn't be
learning to tell the time because I already knew how to tell the time - and, in fact, I could tell it on a 24-hour clock. Yes, I was a bit of a precocious brat.

It didn't do me any lasting harm though - yes I did find primary school boring, by and large, but I read a lot outside of school and eventually the curriculum started throwing things in that I didn't find so easy!