Easy math, but...

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On Facebook, someone posted their status as follows:

I got 288.

Reasoning:

48/2(9+3)=?
48/2=24(9+3)
24(9+3)=24(12)
24(12)=288

I think I used the Order of Operations correctly...

~

Kid who posted it, though, said it's 2. I've predicted his reasoning to be as follows:


9+3 first, and get twelve. Then you'd do 48/2, and get 24. 24/12=2

~

What's the answer?

It would be 2 if it were this problem (I think):

48/2 * (9+3)=?

well the * means you're multiplying, so in that case 288 would be right..

it's been 3 years since I took algebra (god forbid I don't know if I even passed) but you do the parenthesis first, there's just a missing symbol after the 2 and before the parenthesis, for all I know it could even be addition.

I remember being told to do all the work in parenthethicals first. The anwer I came up with was two.

I also saw this question on another website today.

48/2(9+3)
I read this as: 48 / (2 * (9+3) )

Innermost bracketed expression first, so:
(9+3)=12
Leaving 48 / (2*12)

Next outer bracketed expression is an implied multiplication by 2:
2*12=24
Leaving 48/24

So the answer is: 2

But ( ) can be a sign for multiplying, in which case the 9+3 would not be done first, right?

No, it's the 2(...) part.

I was taught that this means the result of the bracketed part is multiplied by 2. (I might be wrong about the description "implied multiplication" - it was a long time ago)
Same as saying "2C", meaning C is multiplied by 2.

Wow, college algebra comes in handy for once...

Just remember the below;

Bracket Exponent Multiply Divide Addition Subtraction

9 + 3 is in brackets, so we get (12)

now, we multiply 2(12) = 24

finally, we divide 48/24 = 2

So it is two

Yay! Someone young enough to remember those damn rules!

That, and the fact that the average Science student has to compute 50 simple sums a minute to pass physics

Yep, that should help.
Me, I just reach for a calculator. My maths brain never really got past the larval stage - I got sold short.

I'm on the same boat, I ignored math until I turned 17 and now I don't seem to have the neurology for crazy stuff like calculus (anything beyond basic integrals, derivatives, and limits). Hopefully that's something I can overcome in the next 60 years.

Here they referred to it as PEMDAS, parenthesis instead of brackets... but meh, close enough.

BIDMAS

Brackets
Indices
Division
Multiplication
Addition
Subtraction

So:

If it is is read as 48÷2(9+3)

48÷2(9+3) =
48÷2*12 =
24*12 =
288

Multiplication and division are equal (as are addition and subtraction), so you go from left to right, which means doing the division first in this case.

However, if you read it as:

48 over the rest of the sum

48 over 2(9+3) =
48 over 2*12 =
48 over 24 =
2

The notation is too confusing.