impaler: Order of operation means
6/2*3 = 9
6/(2*3) = 1


I really can't fathom why so many people are disputing this comment.

Operator precedence is totally arbitrary, and can lead to this kind of confusion. No point in trying to teach it like this... just place parens properly.

tansa: As written, the answer is 9. That is all. Any implementation on a device that gives a different answer is wrong.

dammit. I tried to point this out like 300 posts ago, but the reason the calculators come up with different answers is due to the "implied multiplication." There is no null symbol that means multiplication; it's shorthand that is usually used to mean, eg., that 2x = 2*x. But sometimes, it means, eg., that 2x = (2*x). It depends on what convention you, or more importantly to the discussion at hand, your device is using. ... from TI's website:

Does implied multiplication and explicit multiplication have the same precedence on TI graphing calculators?

Implied multiplication has a higher priority than explicit multiplication to allow users to enter expressions, in the same manner as they would be written. For example, the TI-80, TI-81, TI-82, and TI-85 evaluate 1/2X as 1/(2*X), while other products may evaluate the same expression as 1/2*X from left to right. Without this feature, it would be necessary to group 2X in parentheses, something that is typically not done when writing the expression on paper.

This order of precedence was changed for the TI-83 family, TI-84 Plus family, TI-89 family, TI-92 Plus, Voyage™ 200 and the TI-Nspire™ Handheld in TI-84 Plus Mode. Implied and explicit multiplication is given the same priority.

trappedspirit: optikeye: Conventions have changed..and a poorly presented equation is open to interpretations.

What poorly presented equation?

Anything written in infix notation ever.

tansa: As written, the answer is 9. That is all. Any implementation on a device that gives a different answer is wrong.

Or using a different convention and right. Look at the stone tablets. Look at the golden plates. You won't find operator precedence handed down by the Almighty.

I don't think I've ever seen my current math prof actually use a / or ÷. She always writes a line with numbers above and below, even in printed tests. It's easier to write out on paper, and works just like (x)/(y), eliminating the precedence ambiguity. Then again, she almost never uses a multiplication symbol ether...

orbister: tansa: As written, the answer is 9. That is all. Any implementation on a device that gives a different answer is wrong.

Or using a different convention and right. Look at the stone tablets. Look at the golden plates. You won't find operator precedence handed down by the Almighty.


I should use that when I make a typo or gramatical error. 'I'm not wrong I am using a different convention, one in which I am correct.'

optikeye: Conventions have changed..and a poorly presented equation is open to interpretations.

Done in one 4.5

NateAsbestos: BurnShrike: Bf+: BurnShrike: A = People who don't understand math
B = Those who do
C = Trolls

A ∪ B ∪ C= {This thread}



There are three types of people in this world:
Those who are good at math, and those who aren't.

I'm sorry, but there are 10 types of people in this world.
Those who understand binary, and those who don't.

Actually there are three kinds of people in this world:
Those who extrapolate based on incomplete data.

You're all wrong; there are two kinds of people in this world.
Those who understand discrete math, or those who don't.

HOLY F*CKBALLS I SERIOUSLY HOPE SOME OF YOU ARE TROLLING IF YOU'RE IMPLYING THIS:

Meet Us at the Stick: 6/2(1+2)

Order of Operation says perform the operation in parentheses first

6/2(3)

Now since the only operations left are division and multiplication, perform those from left to right

6/2 = 3

So we are left with

3(3) = 9

It couldn't be more clear.

...IS NOT THE CORRECT AND ONLY ANSWER.

(Otherwise I weep for our education systems.)

/PEDMAS
//Always farking PEDMAS.

Syntax error: unexpected ( in line 1

True of any programming language I can think of. Where else are you writing equations out on one line like that instead of writing them properly and unambiguously?

Oh, and as-written, the correct evaluation of the expression is 9.

babysealclubber: I weep for some of you......

Awwwwww, you *do* care!

Did anyone else learn it as BODMAS?

DarwiOdrade: MunchWolf: 6/2 (1+2) is different than 6/ 2(1+2)

No, it isn't. Spaces are irrelevant.

You know what else is "irrelevant"? The missing symbol between the '2' and the '('.
Interpreting that symbol to be a "*" is no more legitimate than him grouping spaced expressions together. It may be more commonplace, yes, but arguing about interpretation without knowing the convention being used leads to 500 comment threads.

DarwiOdrade: MunchWolf: 6/2 (1+2) is different than 6/ 2(1+2)

No, it isn't. Spaces are irrelevant.

Seriously. People's problems are in assuming the parentheses disappear once (1+2) is solved. Until the implied operation is performed, they don't, and you need to go back to the left side of the equation to get something to operate on the parentheses with:

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

If there is an operation, these would need to be performed in parentheses as well:

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

Where division is expressed explicitly as a fraction (as all division can be), then the leading parentheses are not needed, because they're there by implication, as the denominator is a discrete term in itself:

6
--- (1+2)
2

is not:

6
--------
2(1+2)

but the above is:

6
--------
(2(1+2))

Math threads must be really easy to troll, because this one has a lot of posts.

QED

My samsung stratosphere got 9.

This thread is growing faster than I can read it at work... so let me sum-up...

I weep for the future.

Gaumond: SohCahToa however, that is possibly the greatest and most useful thing ever.

Bash no. 427792:
<@Terror> "It's easy to forget what a sin is in the middle of a battlefield."
<@cky> opposite over hypotenuse
<@cky> dipshiat

My calculator solved 6/2(1+2) with no problem so I tried giving it something harder.



I plugged these into my calculator but it didn't shed any light on the problem.

orbister: Neither is right. It's purely a matter of convention, and it doesn't matter what convention you use as long as you use the same one for creating and evaluation the expression. That's it.

That's like saying that the sequence of letters you use to express a thought doesn't matter, as long as you use the same one for creating and interpreting the sentence. There is absolutely nothing inherent about the shapes in the word "shapes" which means that they should correspond to the notion invoked by the word "shapes".

Yes, in some sense it's 100% true. If in your notes you say that 1+2*3=9 because you're ignoring order of operations, and you're consistent with that, then fine. No harm no foul (unless doing so on your own gets you into practice of doing it when others are watching).

However: when it comes to communicating with someone else, those conventions matter. If you have secretly created your own language I will call Orbisterish where "Neither is right", translated to English, means "Hello, my name is Orbster", you have no right to get angry when you say "Neither is right" and the person doesn't respond "Hello Orbster, it's nice to meet you." Furthermore, you also have no right to get angry if you hand someone a code book and say "this is the language I'm using" and the other person walks away because it's too much work to translate.

In other words, we have the conventions for a reason -- they make it possible to communicate with others. And you can't really go "well I'm changing the convention because it's just a convention" because that is destroying the purpose of the convention.

Clearly the problem is whether 6/2(1+2) represents

(6/2) * (1+2)

or

6
----------
2 * (1+2)

... is the (1+2) meant to be a part of the denominator or not. As it is written, I'd say not, although when I first solved it I fell into the trap of putting it there myself.

gameshowhost: Smiths: disable the Smart/Funny buttons

Son of a biatch. You can do that? I never look at settings and shiat like that.

nah, you can use adblock on them or my Fark greasemonkey script.

1+1 = Mcgurk

If you think the answer isn't 9, you need to be beaten with a sack full of angry weasels.

Meet Us at the Stick: Confabulat: I don't know what's going on here but it frightens and confuses me.

PEMDAS, my friend

Please Excuse My Dear Aunt Sally

Swiss Colony: Grables'Daughter: girls can't do math

Because men (not me ;-)) tell them this:



is eight inches?

: )

Is correct.

Harry Freakstorm: According to my calculator, the answer is Lo Bat

We have a winner.

Grables'Daughter: Swiss Colony: Grables'Daughter: girls can't do math

Because men (not me ;-)) tell them this:



is eight inches?

: )

Is correct.

I don't get it?

/Carpenter
//good at measuring
///sometimes the old jokes are best

dittybopper: Now since the only operations left are division and multiplication, perform those from left to right

Where did this "rule" come from? When I was in school it was multiplication and then division. I was confused that anyone would come up with an answer other than 1. Can anyone explain this new rule to me?

/It's been a long time
//Post "new" math maths?

Aunt Crabby: When I was in school it was multiplication and then division.

What? No. Jesus. It's Parentheses/Brackets, then Exponents and Roots, then Multiplication and Division, then Addition and Subtraction, in the order they're come upon.

2 + 2 / 4 - 1 * 7 / 1

You would read it (and adjust the solving as necessary) as:

Two divided by four, one times seven, seven divided by one, two plus two, four minus one.

Dr. Mojo PhD: What? No. Jesus.

YOU'RE A FUNDAMENTALIST! I KNEW IT!

Xcott: Of course you could learn to spell words without help, but why? It's not the point of a British literature class and distracts from the "flow" of the essay questions.

If your point is "good communication skills are essential" then I agree. But that's not really the issue here; arithmetic is not a communications skill any more than Tetris is a communication skill.

And I would argue that spelling is irrelevant to the discussion of literature, in all but extreme edge cases where the particular (mis)spelling of a word contributes to the meaning of the text.

Arithmetic develops the skill of in-head manipulation, which is necessary for manipulating more abstract things, rapidly.

Tetris develops the skill of in-head manipulation, which is necessary for manipulating more abstract things, rapidly.

Is there some reason I can't practice in-head manipulation of more abstract things directly? What benefit does using arithmetic as a proxy provide? How is that benefit different from using Tetris as a proxy?

We develop tools to help us complete mechanically repeatable tasks. Refusing to use those tools makes you a luddite (in the classical sense). You might be talented enough to pull off your job without the help of such tools, but just think how much better you'd be at it if you freed up the resources you're wasting on such tasks.

Aunt Crabby: Where did this "rule" come from? When I was in school it was multiplication and then division. I was confused that anyone would come up with an answer other than 1. Can anyone explain this new rule to me?

Multiplication is the same thing as division. They can't, logically, be reordered.

profplump: any more than Tetris is a communication skill.

Liszt jolts zits to jilt Lois!