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# 48÷2(9+3) = ? watch

• View Poll Results: 48/2(9+3)
2
117
52.47%
288
106
47.53%

1. Seriously I think the original question is poorly worded and everyone's getting confused

It depends how you write it

48
__
2(9+3)
or
48
__ (9+3)
2
2. (Original post by DanielleT192)
Not meaning to be rude, but is mathematics your area of study? I haven't studied maths in further education, but I don't believe it's necessary for this question.

People are saying that you should be working from left to right. Technically speaking, when you figure out the 2(12) as the brackets takes precendence, then you are still working from left to right. When I studied maths and was presented with big calculations involving brackets I'd put my priority into figuring out the numbers obtained from the brackets and then work out the calculation as a whole.
You don't need higher maths for this. As I said, I think it is year 7 maths.

I'll explain again, in stages:

48 / 2(9+3) expand the operators (to make things easier to understand around the brackets - the 2 isn't inside any brackets)

48 / 2 x (9+3) Now do the brackets, as you have said

48 / 2 x 12 Now go left to right as remaining operators have equal priority

24 * 12

288 Done!
3. (Original post by DanielleT192)
But you're basically saying that 48 divided by 2(12) should be treated as 48 divided by 2 and then multiplied by 12 to obtain the answer of 288 simply because of the arrangement of BODMAS. Multiplication and division are treated equally, as does subtraction and addition and I'm guessing the only reason that BODMAS is spelt that way is to make it easier for people to remember the rule that brackets takes priority in terms of arithmetic equations.

Really, it's the way the question is set out and that is the most important thing. The questioner doesn't expect you to use a calculator to work out this question or have a "computing minded" mode, but use initiative to what you could see. So I still stick to 2, even though it's obvious the question isn't presented well.
you are right about BODMAS but wrong about how to apply the question. Its always left to right for equal priority.
4. (Original post by SsEe)
Brackets first:
48 / 2 * 12
Then do multiplication and division from left to right.
48 / 2 = 24.
24 * 12 = 288
I'm going to side with 2, I'm afraid:

The reason: in my mind "implied multiplication" binds "harder" than explicit multiplication/division.

Otherwise we'd have 3x / 2y = (3x / 2)y =3xy/2, which isn't what we want.

I grant you it's not cut and dried, however.
5. (Original post by Aeschylus)

It depends how you write it
It is written as it is, though. Only in one way. And the answer is 288.
6. (Original post by HistoryRepeating)
How nice for you, but you are wrong. You work out the INSIDE of the brackets first, then apply the usual rules (ie multiplication and division are equal precedence so parse the whole thing left to right)
Okay, ask other people's opinion, even a tutor or teacher and display the question in the same structure that this questioner has displayed it.

I'm genuinely interested in knowing what people's answers are. I'm still sticking to 2 either way.
7. (Original post by Aeschylus)
Seriously I think the original question is poorly worded and everyone's getting confused

It depends how you write it

48
__
2(9+3)
or
48
__
(9+3)
2
In one of those you are reformulating the question from
48÷2(9+3)
to
48÷(2(9+3))

Its 288, it doesnt 'depend' on anything and its not a matter of preference or ambiguity. The rules are clear.
8. Simple BIDMAS tells us its 288.

48/2(9+3)...
48/2(12) BRACKETS
24(12) DIVISION
288 MULTIPLICATION
9. (Original post by HistoryRepeating)
In one of those you are reformulating the question from
48÷2(9+3)
to
48÷(2(9+3))

Its 288, it doesnt 'depend' on anything and its not a matter of preference or ambiguity. The rules are clear.
I'm not going bother responding because I have exhausted all available resources of caring. I'll take your word for it
10. (Original post by DanielleT192)
I'm still sticking to 2 either way.
So even if someone you trust tells you the right answer is 288 you'd continue to give 2 as your answer to this problem. Isn't that a failure of the learning process?
11. (Original post by rmhumphries)
Division has precedence normally, I was taught so in Maths, and usually you expect division to have precedence in the 3rd gen languages I have come across (C, C++, Java, etc).
Division and multiplication have equal precedence in all of those languages. And in general. After which, it depends on associativity. Java, C and C++ all follow left -> right (for the operators in question). So for 48/2*(9+3) they will all give 288.
12. (Original post by DFranklin)
The reason: in my mind "implied multiplication" binds "harder" than explicit multiplication/division.
Where ever do you get that from?
13. (Original post by DFranklin)
I'm going to side with 2, I'm afraid:

The reason: in my mind "implied multiplication" binds "harder" than explicit multiplication/division.

Otherwise we'd have 3x / 2y = (3x / 2)y =3xy/2, which isn't what we want.

I grant you it's not cut and dried, however.
It is completely cut and dried.

To process 3x / 2y as all operators (multiplication and division) are equal priority you parse left to right. Thus all of these are the same:
3x / 2y
((3x)/2)y
3x * 0.5 * y
3xy/2

Whether you 'want' that or not, that is correct.

Its 288, there is no debate. The rules are simple. Left to right on operators of equal priority. 4 levels of priority - 1) inside brackets, 2) indices , 3) multiplication AND division, 4) addition AND subtraction
14. (Original post by DanielleT192)
Okay, ask other people's opinion, even a tutor or teacher and display the question in the same structure that this questioner has displayed it.

I'm genuinely interested in knowing what people's answers are. I'm still sticking to 2 either way.
Again, nice for you, and I'm sure about 70% of people, or more, will get it wrong like you do. However the rules are completely straightforward:
Left to right for operators of equal priority.

Its 288, and this is completely undisputable from a mathematical notation point of view.
15. Definitely 288.
16. Lmao. Read the title and thought

48/2(9+3) = 48/2*12
Multiplication and division have equal precedence so we world left to right.
24 * 12 = 288

I am genuinely embaressed for everybody who has said it is 2. BIDMAS is a simplification of the operator precedence. Division and Multiplication have equal precedence, as do Addition and Subtraction. The fact that the second part is in brackers means ONLY that you do the 9+3 before everything else.
17. (Original post by HistoryRepeating)
It is completely cut and dried.

To process 3x / 2y as all operators (multiplication and division) are equal priority you parse left to right. Thus all of these are the same:
3x / 2y
((3x)/2)y
3x * 0.5 * y
3xy/2

Whether you 'want' that or not, that is correct.
Except I doubt you'd find a single university level textbook, or lecturer, who agrees that 3x/2y = 3xy/2.

At some point you need to take account of what mathematicians really do, rather than some set of rules you learned at GCSE.
18. (Original post by Good bloke)
So even if someone you trust tells you the right answer is 288 you'd continue to give 2 as your answer to this problem. Isn't that a failure of the learning process?
No, it just means that I stick to my ground in when I have an answer and until I get real proof, i.e. from a maths teacher/tutor, then I'd change my opinion. That's when learning comes in.

Also, you were set on the answer being 288 but now you're swaying towards the answer of 2, which shows that you're unsure of your answer too.
19. (Original post by Brocky800)
Simple BIDMAS tells us its 288.

48/2(9+3)...
48/2(12) BRACKETS
24(12) DIVISION
288 MULTIPLICATION
Although you get the right answer its for the wrong reasons.

Division and Multiplication are equal, and BIMDAS is equally valid to BIDMAS.

The reason you do the division first is simply because it is to the left of the multiplication and you work left to right.
20. (Original post by HistoryRepeating)
Again, nice for you, and I'm sure about 70% of people, or more, will get it wrong like you do. However the rules are completely straightforward:
Left to right for operators of equal priority.

Its 288, and this is completely undisputable from a mathematical notation point of view.
I wish I could up vote your post but from the first few pages I've already maxed out today :P

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