This simple math problem went viral (about five million views) on YouTube:

6÷3(1+2)

What is your answer and its justification?

(In reply to re(2): Don't get me started... (but) ... by Charlie)

I will agree that the absence of identifying a system does allow for a greater chance of misunderstanding. The same is true when a short statement is made and the context of it is not made clear nor is the language the statement made is ascertained.  
In regard to the conventions found in the Physical Review Style and Notation Guide, the acceptable order of operations is given for when a vinculum is used. The absence of this mathematical symbol is an indication that the order is not multiplication before division, but the convention that the left-to-right rule of multiplication and division is to be taken as given by the PEMDAS system. Indeed, there can still be confusion when both vinculum and ÷ sign are used without proper use of bracketing. Yet, the implication from the Style Guide is that that mixture of symbols is not following the Style Guide. 
(A note regarding the video: Note that the "actor", when comparing the results of the two calculators, did not use the same expressions. The bracketing used with the two calculators were different, thus the different results. This is evidence that the "actor" imposed a logical fallacy into his argument and did not prove his case.) 

Posted by Dej Mar on 2018-08-10 00:24:40