I would assume this question has been answered before, but no combination of Googling and searching StackExchange yielded an actual response.
The Facebook problem 6/2(1+2) is boring to discuss in terms of PEMDAS/BODMAS/PEMA, but a friend of mine gave me a question I couldn't answer. There are plenty of articles on the origin of this convention. But they always mention in passing that aside from that you evaluate left-to-right.
Where does this come from? I'm assuming this convention was introduced in a country that reads left-to-right. Has there been a time when mathematicians in Arabia, Japan, China, etc. evaluated in a different order?