How to discuss this with the teacher?

[ChocOrange3]

I am FUMING

So, before I unleash I want to take a deep breath and get advice on here.

My DS is in Year 4 and he is very bright and is quite strong in maths. He has learnt some methods at home which he is capable of doing but which are contrary to the schools methods. A couple of weeks ago they were doing multiplication in class and the teacher was teaching them the grid method. DS put his hand up and asked if he could do it his way (the old fashioned column way) and the teacher said to him, in front of the whole class: "what makes you think you are so special and important that you get to do it your way".

I have verified this with another child in the class (who is a very responsible and trustworthy child) who confirms that is what she said.

So I want to convince her to allow him to use his methods if he is proving to be capable and not disrupting the learning of others but more importantly, how do I convey that it is in no way appropriate to talk to an 8 year old like that??

TIA

My ds is using both American and UK site for maths. It seems both do grid/ expanding methods etc., alongside column methods repeatedly through years. I find it useful to know different methods even for able mathematicians. At least my ds isn't complaining.
I find even number lines useful for negative numbers and absolute values which also came up repeatedly.

I am guessing that after spending a significant part of the lesson teaching a method that the teacher wanted the children to practise using the method taught and not do something totally different.

"That's great OPDS. You can do it the way we just learned and then do it your way and check you get the same answer."
Value what he knows already, get him to try the new way. Then get him to explain how the two methods match together.