so far as I know, [BIDMAS] is a creation of some educator, who has taken conventions in real use, and extended them to cover cases where there is no accepted convention. So it misleads students; and moreover, if students are taught PEMDAS by rote without the proviso mentioned above, they will not even get the standard interpretation of a−b+c.

Absolutely rekt.

https://math.berkeley.edu/~gbergman/misc/numbers/ord_ops.html

The rules of Maths that he manages to completely ignore.