Maths... they do still teach it in schools, right?
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I'm on facebook, checking how many awesome friends I have when I see this:
6 - 1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence - but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules' - but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((-1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7 :D
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The minus sign doesn't matter. 6 + 0 is the same as 6 - 0.
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BEDMAS:
- Brackets
- Exponents
- Division, Multiplication
- Addition, Subtraction
= 6 - 1 x 0 + 2 / 2
= 6 - (1 x 0) + (2 / 2)
= 6 - (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
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Well, I ended up doing it right to left and forgetting about the minus/plus precedence - then I headdesked.
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@Charleh said:
or are people just making this maths shit up on the fly?
Only the imaginary numbers.
PADUM-TISH
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@Charleh said:
I'm on facebook, checking how many awesome friends I have when I see this:
6 - 1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence - but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules' - but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((-1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7 :D
*Complains about people not knowing maths.
*Doesn't know maths.
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@Master Chief said:
@Charleh said:
I'm on facebook, checking how many awesome friends I have when I see this:
6 - 1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence - but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules' - but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((-1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7 :D
*Complains about people not knowing maths.
*Doesn't know maths.
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BODMAS, as my maths teacher used to say..
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtractionPut into any spreadsheet and that's the answer.
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@Quango said:
BODMAS, as my maths teacher used to say..
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtractionPut into any spreadsheet and that's the answer.
PEMDAS in these parts. Parentheses, exponents, multiplication/division, addition/subtraction. I swear my sixth grade teacher turned it into a song that we had to sing for a grade.
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@Quango said:
BODMAS, as my maths teacher used to say..
Your Maths teacher was somewhat incorrect; or you're misremembering - the O stands for Orders (exponents and roots).
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtraction
Put into any spreadsheet and that's the answer.
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@Master Chief said:
*Complains about people not knowing maths.
*Doesn't know maths.
THAT is the joke!
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Fucking Maths: How do They Work?
Every time I start thinking that the posters to TDWTF or slashdot are freaking boneheads, I just go over and read a couple Facebook or Yahoo threads. Then I realize what true microcraniality is.
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Minus is right-associative, riiiiiiiiight?
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Don't feed the trolls. It's deliberately intended to be ambiguous, so you'll comment on it. They are trolling for comments and likes. Accounts with a lot of comments and likes are valuable to advertisers.
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@GoatRider said:
Don't feed the trolls. It's deliberately intended to be ambiguous, so you'll comment on it. They are trolling for comments and likes. Accounts with a lot of comments and likes are valuable to advertisers.
What? No it's not, it's perfectly clear.
This one is deliberately ambiguous: a/b(c+d)
Because written as a/b*(c+d) the left to right rule gives this order of evaluation: (a/b)*(c+d).
But the ommited multiplication sign creates ambiguity because that's usually only done in situations where you would have this order of evaluation: a/(b*(c+d)), the same way as writing it out as a fraction gives you implicit parentheses:a
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b*(c+d)
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I was just reading the Excel woes sheet - and it kind of crosses with this thread:
Type this into Excel and be angry:
Cell A1: =-5
Cell A2: =-a1^2+1
Cell A3: =+1-a1^2
You can actually find the history behind this !!fun!! with a search, but it's still irritating. I don't know how many spreadsheets have given me funny results because of this "design choice."
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@too_many_usernames said:
I was just reading the Excel woes sheet - and it kind of crosses with this thread:
Type this into Excel and be angry:
Cell A1: =-5
Cell A2: =-a1^2+1
Cell A3: =+1-a1^2
You can actually find the history behind this !!fun!! with a search, but it's still irritating. I don't know how many spreadsheets have given me funny results because of this "design choice."
Am I missing something?
-a1^2+1 = 5^2+1 = 25 + 1 = 26
+1-a1^2 = +1 - (-5)^2 = +1 - 25 = -24Which is exactly the result I get from Excel...
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@too_many_usernames said:
Cell A1: =-5
Cell A2: =-a1^2+1
Cell A3: =+1-a1^2
A2 has the value of (-5) raised to the second power, with one added to the result.
Do you want it to have the value of (-5) raised to the third power? If so, you need parentheses!
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@joe.edwards said:
The question is on the precedence on the - sign in front of the A1. Either you writeAm I missing something?
-a1^2+1 = 5^2+1 = 25 + 1 = 26
+1-a1^2 = +1 - (-5)^2 = +1 - 25 = -24Which is exactly the result I get from Excel...
or by using the rule that "-A1" is exactly the same as "+ ( -1 * A1 ):-a1^2+1 = -(-5)^2+1 = 25 + 1 = -24
+1-a1^2 = +1 - (-5)^2 = +1 - 25 = -24
The second one, giving 26, seems wrong. Taking the power of 2 of A1 should have precedence over applying the minus sign-a1^2+1 = (-1 * -5)^2+1 = 25 + 1 = 26
+1-a1^2 = +1 + (-1 * -5)^2 = +1 - 25 = 26
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I think the point is that the minus sign in A2 is being treated differently than in A3. Eg, in A2, it has higher priority than the exponent:
=(-a1)^2+1
Instead of
=-(a1^2)+1
Whereas in A3, the minus sign is the subtraction operator, and has a lower priority than the exponent. If you rewrite A2 like this, it matches A3:
=0-a1^2+1
I guess they added logic to handle minus signs in places where subtraction doesn't make sense, like the beginning of the formula, or this:
=5 +- a1
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TRWTF is British English. If it's really "maths", it should be "they do still teach THEM in schools, right?"
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I guess I see it that - can be a unary operator or a binary operator, and that as a unary operator it yields the additive inverse of the number and has immediate precedence, while as a binary operator it has lesser precedence. In any case, it's acting in line with my expectations. -x is evaluated as (-1x).
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@Charleh said:
Well, I ended up doing it right to left and forgetting about the minus/plus precedence - then I headdesked.
In that case you should get 1, not 5.
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@pkmnfrk said:
BEDMAS:
- Brackets
- Exponents
- Division, Multiplication
- Addition, Subtraction
= 6 - 1 x 0 + 2 / 2
= 6 - (1 x 0) + (2 / 2)
= 6 - (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!
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@TGV said:
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!
Is that the one-hundred thousandth person, or the one hundredth to a precision of one thousandth?
(Yes, this is intentional).
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It's the 100'000th person.
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@ekolis said:
TRWTF is British English. If it's really "maths", it should be "they do still teach THEM in schools, right?"
And if it's British English, right? should be innit?
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@TGV said:
@pkmnfrk said:
BEDMAS:
- Brackets
- Exponents
- Division, Multiplication
- Addition, Subtraction
= 6 - 1 x 0 + 2 / 2
= 6 - (1 x 0) + (2 / 2)
= 6 - (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!
I was calling into attention a bit of the story that you clearly did not read:
@Charleh said:
but the correct answer taking that into account is 5.
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My guess...
@pkmnfrk said:
I was calling into attention a bit of the story that you clearly did not read:
@Charleh said:
but the correct answer taking that into account is 5.
= 6 - 1 x 0 + 2 / 2
= 6 - (1 x 0) + (2 / 2)
= 6 - (0 + 1)
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@RTapeLoadingError said:
But clearly wrong, because those two aren't equivalent, since you're introducing a multiplication in the second one.= 6 - (1 x 0) + (2 / 2)
= 6 - (0 + 1)
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@pkmnfrk said:
BEDMAS:
- Brackets
- Exponents
- Division, Multiplication
- Addition, Subtraction
= 6 - 1 x 0 + 2 / 2
= 6 - (1 x 0) + (2 / 2)
= 6 - (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
5 comes from inserting an invisible parentheses that don't belong, opening either before the 1 or the 0 and ending at the end of the statement.
Solving in reverse-polish notation you get:
6 (push), 1 (push), 0 (push), (multiply), (subtract), 2 (push), 2 (push), (divide), (add)
Each operation either pushes a number onto the stack or performs a binary operation between the 2 most recent numbers on the stack.
A subtract subtracts the current value from the one before it on the stack.
An operation replaces the last 2 numbers on the stack with the value of the current one.
Stack looks like this:
(push 6) 6
(push 1) 6, 1
(push 0) 6, 1, 0
(multiply) 6, 0
(subtract) 6
(push 2 ) 6, 2
(push 2) 6, 2, 2
(divide) 6, 1
(add) 7
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Mr CButtius! Will the test be graded on a curve? I did bad on the quiz because my dog was barking and kept me up but I need a C on the test or I won't be able to go to prom!!!
God you people are boring.
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I bring worlds together.
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There, now I got SOME enjoyment out of this thread.