Hey, lately i noticed a question from math that caught my attention.

The equation posed:

48 ÷2(3+9)

Now before we dwelve into the issue of the answer to the problem i feel that some explanations are in order. The equation caught my interest not because of its complexity (obviously) but rather because of how people on different forums decided to solve it.

In general, there are two parties, the first party (mostly people from central Europe and further east) says that the equation equals 2 while the second party answers 288 (as stated by people educated in the western parts of the world). I would like to note that geographical references here are based on my personal findings on the issue.

This difference in outcomes is a result of how people approach the calculation. As i understand, the western countries abide by the PEMDAS rule. According to this approach you first solve what lies within the parenthesis ( so (9+3)=12) after which people would finish the rest of the equation by solving from left to right. This gives us:

48 ÷ 2 * 12 = 24 * 12 = 288

For the second party the equation differs and the approach is that after solving the equation within the parenthesis you continue with calculations that are adjunctant to the parenthesis. In general this means the following:

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

In my opinion the second set of calculations are correct as dictated by what was taught during math throughout my all educational career. An interesting thing is that i have not met with the sign "÷" anywhere else except for North america and maybe England. In Poland we use the sign ":" and "/" out of which the "/" sign is used 99% of the time.

The use of the sign "/" changes the equation quite a deal for me because should i substitute the sign "÷" with "/" the equation is:

48 / 2(3+9)

which can be shown also as

48

_________

     2(3+9)

and this equation leads to the answer "2". This is in the accordance with math laws that state that any division can be shown as a fracture.

My question is, how do you personally solve this equation and which answer do you think is the correct one?

The correct answer is 2, and I'm from the UK.

48÷2(3+9) = 48÷2(12) = 48÷24 = 2

This answer is right becuase of BODMAS

It is what is inside the parenthesis that applies first. After that it should be done from left to right. And so by that logic you shouldn't multiply 2 and 12.

But an equation like this needs a context in order for it to be resolved because I don't think there's one accurate answer.

I'm afraid i am unfamiliar as to what BODMAS stands for, care to elaborate?

You can add/remove parenthesis wherever you want as long as what is inside has been resolved.

Mathematics is a language, and people who solve it to get 48 don't understand the rules ... Brackets, Exponents, Division/Multiplication, Addition/Subtraction, Left to Right

There are different notational systems that could be used, but using in-fix notation (as this equation does) there is no ambiguity; and the correct answer is 48 288.

Edit: I just woke up

http://www.mathsisfun.com/operation-order-bodmas.html


Example: How do you work out 12 / 6 × 3 / 2 ?

Multiplication and Division rank equally, so just go left to right:

First 12 / 6 = 2, then 2 × 3 = 6, then 6 / 2 = 3

I get the answer 2 (add the brackets, multiply the sum in the brackets, and then divide 48 by the answer (24))

Well this equation is  what it is, there are no hidden contexts that you should be aware of, just your math rules that you remember from school. The only catch that i suppose that we could shove in to this is if we applied some rule of exceptions, but to be honest, I don't think that such apply here.

Sorry 288

Edit: I just woke up