Poll: 6÷2(1+2)

6/2(1+2) = ?

  • 9

    Votes: 516 68.9%

  • 1

    Votes: 233 31.1%
  • Total voters
    749
6/2(1+2) is confusing but isn't actually ambiguous - the divisor is just '2' - that is how the '/' symbol is used - there is one answer and that is 9
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Just about beat me to it but thats true! If I am not mistaken(its been a while since I had to deal with such stuff) it was to be 1, there would be a need for extra brackets:

6÷(2(1+2))
 
plasmahal said:
Totally agree with everything you have said there.

My Engineers brain does:

6
_____
2(1+2) and hence I get 1 as the answer.

I asked my daughter who is doing her GCSE's this year and she said 9.

It's all down to how we interpret a poorly constructed sum.

To all those who say it's 9 and don't understand that it can be either 1 or 9 because the of the way it's written, you are all WRONG.
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Standard order of operations: http://en.wikibooks.org/wiki/Algebra/Order_of_Operations#The_Standard_Order_of_Operations

terms inside parenthesis
exponents and roots
multiplication and division
addition and subtraction
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Click to expand...

One procedure, one answer. 9.
 
sk82jack said:
LOL why confuse things even more?

As I said in my first post in this discussion, diving by a number is multiplying by the reciprocal so this would be

9*(1/3)*(1/3)=1

(but can clearly see how you could get to the answer 9 too)
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How can you clearly see that when the standard order of operations says you do these (in priority):

terms inside parenthesis
exponents and roots
multiplication and division
addition and subtraction

Going from left to right.

You can't get 9 out of that unless you are working it out wrongly.
 
gambitt said:
What is your solution for this one please:

9÷3÷3
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1

its the same as 9*(1/3)*(1/3)

and again you've got the potential confusion over people misinterpreting the use of the ÷ operator and coming up with 9

This thread is simply an argument over the definition of the operators (÷ and /) we use to represent division - they're not generally used in mathematics as they can cause confusion.
 
plasmahal said:
Totally agree with everything you have said there.

My Engineers brain does:

6
_____
2(1+2) and hence I get 1 as the answer.
Click to expand...
I don't know why your engineers' brain does that, when you should be thinking beyond GCSE level mathematics and understand the standard order of operations.

parenths, exponents and roots, multiplication and division, addition and subtraction ... going from left to right.
 
plasmahal said:
T

My Engineers brain does:

6
_____
2(1+2) and hence I get 1 as the answer.
Click to expand...

The problem is 6 over 2(1+2) should never be represented with 6÷2(1+2) so its wrong, the correct way to 6/2(1+2) comes out as 9 and 6 over 2(1+2) should be noted as 6/(2(1+2)).
 
dowie said:
1

its the same as 9*(1/3)*(1/3)
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How interesting, you put the 1/3 in brackets. So you calculate:

9÷3 as 9*(1/3) so in more general terms:

x÷y = x*(1/y) [using the same logic as you did above]

But when given:

6÷y [where y = 2(1+2)]

You don't put the y term in brackets.
 
Hatter The Mad said:
I don't know why your engineers' brain does that, when you should be thinking beyond GCSE level mathematics and understand the standard order of operations.

parenths, exponents and roots, multiplication and division, addition and subtraction ... going from left to right.
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Because he has an education beyond GCSE and doesn't need some silly rules to tell him how to read a maths problem. I read it exactly the same way.

No one gives a crap about the 'standard order of operations'.
 
gambitt said:
How interesting, you put the 1/3 in brackets. So you calculate:

9÷3 as 9*(1/3) so in more general terms:

x÷y = x*(1/y) [using the same logic as you did above]

But when given:

6÷y [where y = 2(1+2)]

You don't put the y term in brackets.
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That is different though.

The number 3 is self contained and can be represented by 1/3. 2(1+2) isn't unless you define it as y (and divide 6 by y), or wrap it in brackets.

Pinkribbonscars said:
Because he has an education beyond GCSE and doesn't need some silly rules to tell him how to read a maths problem. I read it exactly the same way.

No one gives a crap about the 'standard order of operations'.
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6/2(1+2) must have 1 answer.

It doesn't map to 2 points.

So what is the answer? Hence we must have an agreed order to answer it.
 
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Hatter The Mad said:
How can you clearly see that when the standard order of operations says you do these (in priority):

terms inside parenthesis
exponents and roots
multiplication and division
addition and subtraction

Going from left to right.

You can't get 9 out of that unless you are working it out wrongly.
Click to expand...

Erm....I don't know why your arguing against me when we both get to the same answer.

I didn't say I believe the right answer is 1, and I didn't say that working it out in such a way is correct.

I just said I can see how people can come to that conclusion.

Take a chill pill, bill :p
 
ghost101 said:
That is different though.

The number 3 is self contained and can be represented by 1/3. 2(1+2) isn't unless you define it as y (and divide 6 by y), or wrap it in brackets.
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Is 'self contained' a mathematical term? How is it defined?

3 is just a simplified way of writing 1*3 just as 6 is a simplified way of writing 1*6 or 2+4 or 2(1+2) etc.
 
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