
Seems silly, but try solving more complex equations without using it. You can't.
I can't remember being taught it at school either. I came across it in 'Advanced Homework for Adults' last year.
( , Sun 5 Jun 2011, 11:45, Reply)

and altho some folks seem confused as to what the O is I know and knew ALL parts the acronym stands for, I simply was never told there was a set order of execution if no brackets or exponents were present.
God my mind is literally blown that I've got THIS far in life without knowing that, weird!
*goes to lie down*
( , Sun 5 Jun 2011, 12:03, Reply)

I'd met brackets by that point, but the notion of powers was utterly alien at that stage.
( , Sun 5 Jun 2011, 12:19, Reply)