Poll: 6÷2(1+2)

[Nitefly]

6÷2(1+2) = x/y when:

x = 6

y = 2(1+2) ---> 2(3) ----> 6

Thus x/y = 6/6 = 1

Surely?

 

[sambos1234]

It's like being back at shcool ... PLEASE - no more maths!!!

 

[qqg3]

6/2(1+2)
6/2(3)
6/2x3
6/2 = 3
3x3= 9

No?

That's what I was taught.

 

[Scon]

Bidmas is clearly fallible if people are justifying an answer of nine with it.

6÷2(1+2)

6 is ONE term.
2(1+2) is ANOTHER term.

In order to achieve a result of 9 you would need:
6(1+2)÷2

It is entirely possible this problem was introduced to highlight the flaws of the BIDMAS rule.

wrong, wrong, wrong WRONG!

 

[Nitefly]

He's moving the 6 to the other side of the equation and making it a multiplying factor of X to cancel it out on the other side of the equation, simplifying it.

That would only make sense if it was 2(1+2)÷6 wouldn't it?

 

[vincent1989]

I see your A* at GCSE and raise you an A at A-Level and a maths degree

Unless I'm misunderstanding something in what you're saying, you're finished with the brackets once you have worked out the contents.

6 / 2 * (1+2) is exactly equivalent to 6 / 2 * 3

i raise you're degree and A level with the correct answer. 1.

 

[Pinkribbonscars]

Jesus, there are a lot of stupid people in this thread.

Honestly, I think a lot of people who aren't stupid with maths would go for 1 - I instinctively turned that ÷ sign into a /, which would be:

6/2(1+2)

Which definitely is 1.

 

[Barks]

Can anyone doing a PhD or MSc in mathematics or a related degree give an opinion.

I appreciate some people are using order of operations rules to justify various answers however I have an inkling this problem is a special case used to highlights the flaws of the procedure.

 

[muon]

i raise you're degree and A level with the correct answer. 1.

I don't think Mathematica is wrong.

Can anyone doing a PhD or MSc in mathematics or a related degree give an opinion.

I appreciate some people are using order of operations rules to justify various answers however I have an inkling this problem is a special case used to highlights the flaws of the procedure.

You don't get asked to do something like this above school. You don't get such ambiguous sentences in Mathematics because when you use the / operator you wrap the nominator and denominator in brackets.

 

[Strife212]

How can it feasibly be 1, it's just wrong, BIDMAS,

6/2(1+2) = 6/2(3) = 3(3) = 9

 

[ikillbears]

http://lmgtfy.com/?q=6÷2(1+2)+

 

[LizardKing]

I find it easiest to explain by introducing X into the equation

6÷2(1+2) = X
2(1+2) = 6X
2+4 = 6X
6 = 6X
1 = X

It has been a long long time since i've ever done any math though.

Forgive me here but were does the 4 come from? ( 2+4=6x )

 

[Eric's collar]

I have a friend called casio and he says it's 9.

 

[Nitefly]

B Brackets first ------------- 6÷2(1+2) -----> 6÷2(3) ----> 6 ÷ 2 x 3
O Orders (ie Powers and Square Roots, etc.)
DM Division and Multiplication (left-to-right) -- 6 ÷ 2 x 3 ----> 3 x 3 ----> 9
AS Addition and Subtraction (left-to-right)

Well, what do you know, it is 9, assuming the left to right rule is right.

I was always taught that multiplication always came before division.

 

["andy"]

i love these threads

always bring out the people who dont know what theyre on about but pretend that they do

tip for those saying 1 ... stick it in your calculator

 

[Haircut]

Can anyone doing a PhD or MSc in mathematics or a related degree give an opinion.

I appreciate some people are using order of operations rules to justify various answers however I have an inkling this problem is a special case used to highlights the flaws of the procedure.

It's a misunderstanding based on the fact that there is no explicit multiplication sign between the 2 and the (1+2) and therefore people are making the assumption that they should treat them as one term IMO.

Similarly, you could have the equation x / 1 * x and ask it is equal to x^2 or 1.
Applying the order of operations correctly the answer is x^2, but I would imagine lots of people who are saying the answer to your original question is 1 would pick 1 here as well, even though there is nothing in the equation that says I need to calculate 1 * x first.

 

[QlimaxUK]

wheres all this '2(1+2)' coming from? 6÷2=3!!!!!! not 2!

and how do you do that ÷ symbol i always have to use / for divide

(and before quoting me i copied and pasted the ÷ into this post so don't say 'you did it!')

 

[Morba]

As there is no operator in 2(2+1) people are assuming you do the whole thing to work out the bracket. In reality you don't, it's 2x(2+1), so 2x3. In the whole equation this would not = 6 as the division is first, making it 3x3.

Unless I'm doing something wrong, which is possible

 

[Viper²]

Honestly, I think a lot of people who aren't stupid with maths would go for 1 - I instinctively turned that ÷ sign into a /, which would be:

6/2(1+2)

Which definitely is 1.

The confusion comes when some have learnt BODMAS and others have learnt PEDMAS. The latter states division comes after multiplication.

 

[vincent1989]

i love these threads

always bring out the people who dont know what theyre on about but pretend that they do

tip for those saying 1 ... stick it in your calculator

Answer is 1 as has been mentioned 6 is one expression and 2(1+2) is another expression. Plus my scientific graphic calculator has worked it out as 1.