Had a similar experience in what I think must have been my second year of primary school.

I was asked to go through a math problem that was written out, something like “4 + 7 = ?”.

I said “Four plus seven equals eleven”.

The teacher said that was wrong and said “Four add seven is eleven”.

I’m like, what is the difference? She says, we aren’t onto “plus” and “equals” yet

Six year old me spent an unreasonable amount of time trying to figure out how their was some difference between plus and add. She just could have said “they are the same, but please use these words to describe them in our lessons”.