The background is:
Our maths teacher probably isn't great. My impression of her is that she looks like the painfully shy type. She looked a bundle of nerves at the first parents evening and seemed very defensive.
My dd says she spends a lot of time screaming in class. (For maths the class is divided into two groups but despite the smaller size, obviously dc are being loud or somehow disruptive if the teacher is screaming a lot). Dd doesn't seem to mind the teacher but hates the screaming, hates maths.
Dd absolutely didn't get the maths they were being taught (year 1). In the end I taught it to her myself so she's ok with it now. I teach her at home, she then goes over it again in school and we're on top of it. Ideally I'd prefer her to learn it well in school but that's the way of it. I assumed it was just dd who was having problems with it but apparently not.
Other parents have the same problem. Their dc don't understand what is going on in maths, they're totally lost. I think a) she has trouble controlling the class although the class teacher doesn't b) she can't explain maths very well if no one is getting it c) she's very defensive so difficult to approach