Math Simple mathematical problem

[Lambo]

I've browsed some forums and saw an interesting mathematical question.
Is 48÷2(9+3) equal to 2 or 288? I thought the fine folks here at OF might want to try and answer.

 

[dbeachy1]

The answer, naturally, is 288. :tiphat:

 

[HAL9001]

I would say 2, but I'm not sure...

 

[Artlav]

Sequencing of arithmetic operation, first year of school or last days in kindergarten.

 

[Grover]

Id say 2 because the bracket seems attached to the 2, there is no sign between them, so i imagine it is part of the bracket function which comes first in bidmas

 

[N_Molson]

I always learned that the parenthesis have the absolute priority over the other operators. So :

48 ÷ 2 * (9+3)=
48 ÷ 2 * (12)=
48 ÷ 2 * 12=
24 * 12=
288

By convention, the order of precedence in a mathematical expression is as follows:

* Terms inside of Brackets or Parentheses.
* Exponents and Roots.
* Multiplication and Division.
* Addition and Subtraction.

 

[orb]

1B0_hex = 432_dec But I voted 288.

i imagine it is part of the bracket function which comes first in bidmas

[ame="http://en.wikipedia.org/wiki/Order_of_operations"]Order of operations - Wikipedia, the free encyclopedia[/ame]

It's a contraction and not a bracket function:
2x = 2 * x = 2(x) = 2 * (x)

 

[Fabri91]

I said 2.
48÷2(9+3)
48÷2(12)
48÷24
2

Thought that the parenthesis had higher priority.

 

[HAL9001]

Is it this way: 3/5*4=3/20=0.15 or this way: 3/5*4=0.6*4=2.4
I think the second one, so it would be 288, but I think we need a "correct" order for this.

 

[Linguofreak]

I said 2.
48÷2(9+3)
48÷2(12)
48÷24
2

Thought that the parenthesis had higher priority.

The priority of the parentheses applies to what's inside it, so the parentheses prevent:

48/2*9+3
24*9+3
216+3=219

But it doesn't apply to what's outside the parentheses. The multiplication doesn't happen before the division just because it's *next* to the parentheses.

That said, I made a different error the first time I saw this (maybe a week or two ago) that led to the same result you got: I thought multiplication always came before division and addition before subtraction, but actually it's "multiplication and division together in order of appearance, then addition and subtraction together in order of appearance".

So for this problem, the correct order of operations is:
(9+3)=12
48/2=24
24*12=288

It's equivalent to the reverse polish notation problem 9 3 + 48 2 / *.

 

[Face]

Let's see. If I take this as order rules, it would be 288, given that simple concatenation of number and parenthesis is defined as multiplication.

If I take the [math]\div[/math] sign as serialized operator for [math]\frac{48}{2(9+3)}[/math] it'd be 2. After all, the sign is a pictogram for this usage...

So in this case, your problem is not defined sufficiently IMHO. If I had to guess, though, I'd take the 288, as it sounds like a "even primary school kids know that!" kind of question .

regards,
Face

 

[Izack]

Let's see. If I take this as order rules, it would be 288, given that simple concatenation of number and parenthesis is defined as multiplication.

If I take the [math]\div[/math] sign as serialized operator for [math]\frac{48}{2(9+3)}[/math] it'd be 2. After all, the sign is a pictogram for this usage...

So in this case, your problem is not defined sufficiently IMHO. If I had to guess, though, I'd take the 288, as it sounds like a "even primary school kids know that!" kind of question .

regards,
Face

Agreed there. I always avoid using the division pictogram for this very reason.

 

[Artlav]

Looks like mathematics, like any language, have it's dialects.

 

[statickid]

no the pictogram means

48
--*(9+3)
2

---------- Post added at 07:26 AM ---------- Previous post was at 07:24 AM ----------

put into a graph calculator, the calculator will know this as well

---------- Post added at 07:27 AM ---------- Previous post was at 07:26 AM ----------

@Face, your problem would look like this

48/[2*(9+30]

otherwise only the 2 is on the bottom

 

[RisingFury]

YouTube - 2x2=5? Good math trick!

Wrong!
B - C - A equals 0! You can't divide by 0!

 

[Grover]

Wrong!
B - C - A equals 0! You can't divide by 0!

the probe can... and so can chuck norris for that matter. i think it came out as pi :rofl:

 

[mc_]

48÷2(9+3) means 48÷2*(9+3), * is just not written.

So,inside the "()" first, and then left to right (as there is no "+" or "-", and "÷" has the same priority with "-"): 48÷2*(9+3) = 48÷2*12=24*12=288. Simple task for a six years old child.

P.S.: who said mathematics is not a language?

 

[jthill]

I read ÷ as \over: $48\over2(9+3)$.

 

[Notebook]

I must admit I read it as 48/24, but looking at it later I should have read as left to right the correct answer. Algebra, isn't it Luferdnowl?

N.

 

[Tom_Backhouse]

!@**%! So, yeah, division before multiplication. I'm not an arithmetician. (apparently).

EDIT: Thinking this through a bit more, inexcusable as it is, I'm used to seeing

Instead of

, of which the former is a little clearer, and obviously more used. Thus I have a tendancy to forget BIDMAS when the latter notation is used. (images came from wikipedia btw)