different places teach different conventions
But they all teach the same rules
some places say that PEDMAS is a very strict order
Which is totally fine and works
Other places say that it is PE D|M A|S,
Which is also totally fine and works
even in this post, say it’s PEMDAS
Also totally fine and works
it’s simply a matter of if the people talking agree on the convention to use
No-one has to agree on any convention - they can use whatever they want and as long as they obey the rules it will work
can’t agree on
Educated people agree that which convention you use doesn't matter.