48÷2(9+3) =

PEMDAS, man, PEMDAS!

 

7.41

 

Why think, when you have Google ? Google says it is equal to
(48 ÷ 2) * (9 + 3) = 288

The rule, however, is left to right for operations of equal precedence unless parantheses tell you to do something else.

 

Correct. You do the addition first, since it's in the parentheses, which gives you 12 at that point. Then you go back and do the division and multiplication from left to right, since it has equal precedence.

Tom

 

Well, that's scary.

 

In Excel, if you do in a cell : =48/2(9+3)
At first it complains, expanding it to: =48/2*(9+3)
Then gives 288.

This would also be :
a / b (c+d)

 

I must admit, I need another explanation. If it were (48/2)(9+3), of course it's 288, but as written I see 48 over 2(9+3). Go math folk, explain

 

This is harder than regenerative braking divided by 1000kw times MPGs! eeek....

 

How is this difficult? :huh:

I learned this in 6th grade. It's 2.

 

Is that your final answer?

 

fourth grade, it's 288.

 

As a contrary voice, you can go to a site like:

PlanetMath: order of operations

There you get multiplication prior to division. So that approach gives 2.

Likewise, if you buy 1,000 beers in Europe, how much have you drunk?

 

I still disagree. For those telling me I should check my 4th grade math (bisco!! ), I did get a 780 on the math part of the SAT back in the day

It's irrelevant that's it's written in one line. The division sign in general is a visual representation of what it stands for, not just two dots and a line. The top dot represents the top value of a fraction, defined by the value found prior to the division sign, the line is of course "divided by", or the fraction line, and the bottom dot the value following it.

Furthermore, parentheses imply a "doing out" of all attached to those parentheses (or brackets, for those using that terminology). The 2 in the problem is a coefficient in this case. This supersedes the left to right stuff. Another way to think of this is 48÷2x, where x=9+3. In that case it's quite clear you would never do the division first, and that's what we have here.

If you had written 48÷2*(9+3), it's different...but you didn't! Answer is 2.

Found some extra reading - you can see a TI calculator will compute that as 2, unless you separate (9+3) from its coefficient.

The Order of Operations: More Examples

 

Not according to Wikipedia:

"Similarly, care must be exercised when using the slash ('/') symbol. The string of characters "1/2x" is interpreted by the above conventions as (1/2)x. The contrary interpretation should be written explicitly as 1/(2x). Again, the use of brackets will clarify the meaning and should be used if there is any chance of misinterpretation."

I believe that if there were some unambiguous convention in that regard Wikiedia would record it, but all I've been able to find is that juxtaposition in lieu of an explicit multiplication operator while common and accepted practice is NOT unambiguously assigned precedence over conventional computation sequence.

I for one try not to take chances and use parentheses prolifically. They don't cost anything and they eliminate arguments.