Poll: 6÷2(1+2)

6/2(1+2) = ?

  • 9

    Votes: 516 68.9%

  • 1

    Votes: 233 31.1%
  • Total voters
    749
Pinkribbonscars said:
No, no one with any maths experience would write it that way. Those with experience know how to 'parse' the problem in the OP according to the 'rules', but it should never be written that way as it is unconventional.
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Oh, yes. I agree with you. It is bad form - that's for sure. I was just saying that this shouldn't be an excuse for arriving at the wrong answer - if you parse it correctly, you get the right answer whether it is written with a / or a divide symbol.
 
vonhelmet said:
And just when am I ever going to have to solve this sort of sum when I don't know sufficiently what I'm doing to write it in a sensible fashion?
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I don't know, but ignorance is not an argument against fact - it is not ambiguous. There is a universally accepted way of parsing expressions, and when you follow it you arrive at the right answer: 9.

What you said about anyone with mathematics experience above year 10 say it is ambiguous. That's plain wrong, no matter what the consensus here.

Yes the OP included an expression that was written in bad form, but parse it using the standard order of operations and you get the right answer: 9.
 
Hatter The Mad said:
I don't know, but ignorance is not an argument against fact - it is not ambiguous. There is a universally accepted way of parsing expressions, and when you follow it you arrive at the right answer - 9.
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Regardless, the sum in question is of no interest as it is never a sum that I am going to come across except in a GCSE maths paper. In the real world, when I find myself doing maths, BIDMAS is of no concern to me, as I will write things properly.
 
vonhelmet said:
The funny thing is that all this BIDMAS business is great for passing your GCSE maths exam, but once you get into actually using that maths for anything useful, you'd expect it to be more clearly written, not least because if, say, you were solving an equation as part of a physics or engineering problem, you'd be the one working from one line to the next so you'd know what you were talking about. It's not like you're solving a problem and you go from one line to the next and suddenly think "Oh no! This doesn't make sense! BIDMAS TO THE RESCUE!". Unless you're a fool with the memory of a goldfish you'd know what you were doing on the previous line and you'd bracket accordingly as you moved to the next one to keep things clear.
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In complete agreement.
 
Hatter The Mad said:
The way it is written here is only a problem if people don't know how to properly parse expressions.


Anyone with experience above year 10 should be familiar with the standard order of operations, which can only give the answer of 9 when followed. If they're not familiar with it and get an answer of 1, they should get familiar with it and try again.
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The way it is written here is clearly a problem, since so many people disagree on the result. You can't communicate poorly and then expect everyone to understand what you meant.

In fact, that is the entire reason mathematical notation has developed the way it has, ever since the sixteenth century: to ensure that problems could be written in a clear, concise manner that everybody could understand the same way regardless of language.

In that sense, this problem has clearly failed.
Hatter The Mad said:
Anyone with experience above year 10 should be familiar with the standard order of operations, which can only give the answer of 9 when followed. If they're not familiar with it and get an answer of 1, they should get familiar with it and try again.
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The thing is, there are no operations to prioritise as the problem has been written. You do the addition first, of course (since the problem has told you to do so via the use of brackets), and then what? You're left with three multiplications - whose order, I will remind you again, shouldn't matter thanks to the associative and commutative properties the real numbers are endowed with when it comes to standard multiplication.

The issue you're left with is what to multiply by. Either we want to multiply by 3, or by 1/3. Whoever has written this problem hasn't made it clear enough which of these they'd like you to do, and whilst you could certainly take a gamble that they meant multiply by 3, you cannot be sure because of how poorly written this problem is.
 
vonhelmet said:
Regardless, the sum in question is of no interest as it is never a sum that I am going to come across except in a GCSE maths paper. In the real world, when I find myself doing maths, BIDMAS is of no concern to me, as I will write things properly.
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I agree with you - things should be written properly.

But just because they aren't, as in this case, does not mean it is okay to be wrong about it and then argue against fact until people are blue in the face just because they are ignorant to the correct way of parsing expressions.

That's all.
 
Hatter The Mad said:
Oh, yes. I agree with you. It is bad form - that's for sure. I was just saying that this shouldn't be an excuse for arriving at the wrong answer - if you parse it correctly, you get the right answer whether it is written with a / or a divide symbol.
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In practise though, you don't think of the rules when solving a problem, as they are written in a standard, clear, way. I am not used to seeing problems written as in the OP, so I convert it in my head to how it should be written. I read it as 6 over 2(1+2), which equals 1. This isn't correct according to BODMAS but it is how I, and I suspect others, read it.

The division symbol should never be used.
 
Killerkebab said:
Then that sense, this problem has clearly failed.The thing is, there are no operations to prioritise as the problem has been written. You do the addition first, of course (since the problem has told you to do so via the use of brackets), and then what? You're left with three multiplications - whose order, I will remind you again, shouldn't matter thanks to the associative and commutative properties the real numbers are endowed with when it comes to standard multiplication.

The issue you're left with is what to multiply by. Either we want to multiply by 3, or by 1/3. Whoever has written this problem hasn't made it clear enough which of these they'd like you to do, and whilst you could certainly take a gamble that they meant multiply by 3, you cannot be sure because of how poorly written this problem is.
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The rule says you parse left-to-right. It isn't just about parsing priority, it is about order too; and the order is left-to-right.

If you follow the rule, it isn't ambiguous what to do. There is only one interpretation and one answer: 9.
 
Anyone stating the answer is definitely 1 or 9 are both wrong.

Where does it state it is in base 10, could be base 7 or hexadecimal which would throw another spanner in the works. ;)

Again anyone claiming that the original equation is not ambiguous are very foolish and I wouldn't trust them to do any numeric programming or equations in the real world!
 
Hatter The Mad said:
I agree with you - things should be written properly.

But just because they aren't, as in this case, does not mean it is okay to be wrong about it and then argue against fact until people are blue in the face just because they are ignorant to the correct way of parsing expressions.

That's all.
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I would contend that the rules are redundant, when such an expression will never arise in real life, outside of an exam.
 
Hatter The Mad said:
Well, that is wrong. It has risen here and it rises whenever a programmer is programming a calculator. There are two real-life examples for you.
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It's arisen here as a troll to get people to argue. This is not a real life application.

And the programming of a calculator to solve a question like this is only relevant when programming a calculator to solve GCSE maths problems with no real life application. RECURSION.

When I was a lad, if you wanted to solve a problem like this in a calculator, you bracketed it yourself and fed it in. Although frankly, I'd be embarrassed to do a sum like that on a calculator.
 
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