6÷2(1+2)=?

I tried 2 different calculators. My Casio scientific says 1. My TI 86 graphing says 9. I concede that this problem is indeed written poorly and judging by the 7 pages of discussion, definitely open to interpretation.

Originally posted by Whatsreal

Originally posted by ASeeker343

Originally posted by Whatsreal
wow!!

how many ATSers does it take to do a simple math problem...

I was a Math teacher for 8th grade algebra...

PEMDAS

Parenthesis
Exponents
Multiply
Divide
Add
Subtract

6 / 2(1+2)

1+2 = 3

2*3= 6

6/6 = 1

Seriously, my heart is broken that this has required an entire thread. This is why America is weak.

Why did you multiply before you divided? That action is inserting parenthesis that arent there. The division should be done first.

NO!!!! you get an F for today... I am a certified math teacher.. I'm not inserting parenthesis that aren't there as there are already there...

and PEMDAS... M before D.. multiple before divide... THINK BEFORE YOU SPEAK. Don't speak if you don't know.... man... no wonder the rest of the world laughs at us... kids in elementary school know this in most european countries.

MULTIPLY BEFORE DIVIDE... got it?

No I dont got it. And Im glad i didnt take your class. The order of operations does not say multiply before divide. Those two operations are interchangeable, and once the problem is simplified they are performed left to right. Do you add everything before you subtract? What is 3-4+5? 4. Same concept with multiplication and division. Left to right.

Heres a link if you dont believe me. www.math.com...

6÷2(1+2)

Do the parentheses

6÷2(3)

The above multiplication is implied by the parentheses. a(b) = a*b

The parentheses do not imply that the multiplication must be performed first.

Order of operations, multiplication and division, left to right. 6÷2*3
3*3=9

If you still arent convinced:

www.youtube.com...

Ive been through calc III so i dont need your 8th grade algebra lessons. The division sign does not put everything after it into the denominator. Granted if this were a textbook problem it would probably be written more clearly but still...

facepalm

reply to post by Earthscum


calculators do not speak algebra! Algebra was invented as a way for humans to communicate with more complex numbers.... computer chips speak in 1s and 0s...

that said..

I used wolfram software to help me as I was learning Calc 1,2 and 3.... guess what... half the time it was wrong because it doesn't do algebra well.. I had to enter in bits of the equations i needed in pieces so that the order of operations was followed and other laws, like the distributive law were followed properly.

I don't know why they don't work right (calculators and software) but I assure you I am right....

and to the guy who said his 16 core comptuer is right and I'm not.... trying using the single core above your shoulders

Originally posted by Whatsreal

Originally posted by ASeeker343

Originally posted by Whatsreal
wow!!

how many ATSers does it take to do a simple math problem...

I was a Math teacher for 8th grade algebra...

PEMDAS

Parenthesis
Exponents
Multiply
Divide
Add
Subtract

6 / 2(1+2)

1+2 = 3

2*3= 6

6/6 = 1

Seriously, my heart is broken that this has required an entire thread. This is why America is weak.

Why did you multiply before you divided? That action is inserting parenthesis that arent there. The division should be done first.

NO!!!! you get an F for today... I am a certified math teacher.. I'm not inserting parenthesis that aren't there as they are already there...

and PEMDAS... M before D.. multiple before divide... THINK BEFORE YOU SPEAK. Don't speak if you don't know.... man... no wonder the rest of the world laughs at us... kids in elementary school know this in most european countries.

MULTIPLY BEFORE DIVIDE... got it?

edit on 1-5-2011 by Whatsreal because: had to fix grammer

wow, it would seem someone needs some re-certification ...
any integer directly connected to parenthesis ex: x(2) is a multiplication order which is always performed before division in said example posted in this thread.

you are correct, multiply does occur before division however, in your rant ...you fail to recognize the order to multiply ... hence: 6 divided by 2(times)(2 plus 1)
IF you follow your own instructions, the only answer is "1".

ps: the correct algebraic equation that reflects your statements would appear ... Solve x ~~ (6/2)(2+1)=x or similar.

P.E.M.D.A.S.
It's gotta follow the orders of operation; parenthesis, exponents, multiplication, division, adding and subtraction

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

or

6/2(1+2)
6/2+4
6/6
1

Any other way is incorrectly ordered math.

Originally posted by ASeeker343


6÷2(1+2)
6÷2(3)
6÷2*3
3*3=9


facepalm

Your steps are wrong, you said yourself that you must do the parenthesis.

Originally posted by ASeeker343

The above multiplication is implied by the parentheses. a(b) = a*b

The parentheses do not imply that the multiplication must be performed first.

Although the first is true, the last is not in this case; 2(a+b)=(a+b)(a+b) properly applying this rule is what you're missing.

You guys are making me lol all over the place.

www.mathsisfun.com...

edit-Teacher guy, I don't like the way you talk down to people. I had teachers like you and they were usually wrong and were just plain mean to students to make then drop the subject and accept bull. This isn't your elementary class.

Originally posted by Karmatic
I tried 2 different calculators. My Casio scientific says 1. My TI 86 graphing says 9. I concede that this problem is indeed written poorly and judging by the 7 pages of discussion, definitely open to interpretation.

Star for you.

There's a big difference between 6÷(2(1+2) ) and (6÷2)(1+2). None of the calcs I tried came up with 1. They all did brackets first, then the equation in line (6÷2x3). The way I learned math was to do all the math in line as it's written if there's no brackets, just like reading left to right. I had it also explained to me that is bad form to write problems like that because of just this type of situation.

Originally posted by JackyMenace
You guys are making me lol all over the place.

www.mathsisfun.com...

This link also contains the correct way. Scroll down to 30÷5*3 and be enlightened!

Good find

Originally posted by JackyMenace
You guys are making me lol all over the place.

www.mathsisfun.com...

edit-Teacher guy, I don't like the way you talk down to people. I had teachers like you and they were usually wrong and were just plain mean to students to make then drop the subject and accept bull. This isn't your elementary class.

edit on 2-5-2011 by JackyMenace because: fun

Well, at least I wasn't taught wrong...

"Otherwise just go left to right"

(obviously doing M/D first)

I mainly remember because it's done in the reverse of what we are taught. We are taught addition and subtraction first, then mult/divis, etc.

reply to post by ASeeker343

the only problem with your link is that this equation (as written) doesn't even appear as an example.
since you don't dare offer an answer (1 or 9), how do you interpret your 'link' information?
the above link does not offer ANY example resembling the equation posted within.

Originally posted by Whatsreal
reply to post by Earthscum

 

calculators do not speak algebra! Algebra was invented as a way for humans to communicate with more complex numbers.... computer chips speak in 1s and 0s...

that said..

I used wolfram software to help me as I was learning Calc 1,2 and 3.... guess what... half the time it was wrong because it doesn't do algebra well.. I had to enter in bits of the equations i needed in pieces so that the order of operations was followed and other laws, like the distributive law were followed properly.

I don't know why they don't work right (calculators and software) but I assure you I am right....

and to the guy who said his 16 core comptuer is right and I'm not.... trying using the single core above your shoulders

The majority of this is true, especially when it comes to computer code. However, scientific calculators are programed to properly interpret order of operations especially in cases like this. Thus if i enter this into my calculator i get 9. In order to get 1 i need an extra set of parentheses 6÷(2(1+2)) which are incorrect.

Originally posted by Earthscum

Originally posted by Karmatic
I tried 2 different calculators. My Casio scientific says 1. My TI 86 graphing says 9. I concede that this problem is indeed written poorly and judging by the 7 pages of discussion, definitely open to interpretation.

Star for you.

There's a big difference between 6÷(2(1+2) ) and (6÷2)(1+2). None of the calcs I tried came up with 1. They all did brackets first, then the equation in line (6÷2x3). The way I learned math was to do all the math in line as it's written if there's no brackets, just like reading left to right. I had it also explained to me that is bad form to write problems like that because of just this type of situation.

I agree about the interpretation thing. That's why I am lolling.

Quote from wikipidea (not saying it's a reliable source but whatever) - "In the United States the acronym PEMDAS is common. It stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. If PEMDAS is followed without remembering that multiplication and division have the same weight, and addition and subtraction have the same weight. Doing multiplication before division, can give the wrong answer."

reply to post by Honor93


The youtube link has this same problem with different numbers. If you cant follow it and substitute the numbers from the OP's problem in for yourself you probably shouldnt be participating. Ill break it down for you tho anyway.

In the video:

48÷2(9+3)
48=a
2=b
9=c
3=d
a÷b(c+d)

now the OPs numbers...
6=a
2=b
1=c
2=d

6÷2(1+2)

Same concept, same process. Answer is 9

if that doesnt clear it up for ya then i dont know what to tell ya

Edit: and if you are referring to the other link, that was just to illustrate that multiplication and division are performed left to right at the same time... before any addition and subtraction

Originally posted by ASeeker343
However, scientific calculators are programed to properly interpret order of operations especially in cases like this. Thus if i enter this into my calculator i get 9. In order to get 1 i need an extra set of parentheses 6÷(2(1+2)) which are incorrect.

hahahahahahaha, thanks for that ... but i gotta ask, really?
as you state above, in order for the calculator to perform correctly, you have to add parenthesis ... even though the equation, as written, explicitly gives the order to multiply simply by rule of juxtaposition (or by placing the integer 2 directly next to the parenthesis) ... apparently, this is common knowledge by most except some teachers and most programmers ... understandable, many of both attended school alongside me.

Just print this thread out and hand it in.

reply to post by ASeeker343


Either you're tolling or don't understand math.

The division symbol is as good as saying:

__6__
(2(1+2))

To solve fractions you have to solve the denominator first.

Originally posted by Honor93

Originally posted by ASeeker343
However, scientific calculators are programed to properly interpret order of operations especially in cases like this. Thus if i enter this into my calculator i get 9. In order to get 1 i need an extra set of parentheses 6÷(2(1+2)) which are incorrect.

hahahahahahaha, thanks for that ... but i gotta ask, really?
as you state above, in order for the calculator to perform correctly, you have to add parenthesis ... even though the equation, as written, explicitly gives the order to multiply simply by rule of juxtaposition (or by placing the integer 2 directly next to the parenthesis) ... apparently, this is common knowledge by most except some teachers and most programmers

... understandable, many of both attended school alongside me.

I was never under the impression that the parenthetical multiplication by juxtaposition was explicitly ordered to be first. Thus I am proposing the correct answer to be 9. Parenthetical multiplication is implied multiplication. 2(3) = 2*3. Once the argument inside the parentheses is solved they are irrelevant. At that point its left to right multiplication and division.

Are you telling me that 6/2(3) is different than 6/2*3? If so i would disagree

Originally posted by MallardDuck
reply to post by ASeeker343

 

Either you're tolling or don't understand math.

The division symbol is as good as saying:

__6__
(2(1+2))

To solve fractions you have to solve the denominator first.

Not trolling. This is the problem, everyone is interpreting it as a fraction. Not the case. Check my links from earlier.

This is a good one too

www.mathsisfun.com...

scroll down to 30÷5*3 and see what i mean

reply to post by MallardDuck


Read the thread title.

Originally posted by ASeeker343
reply to post by Honor93

 

The youtube link has this same problem with different numbers. If you cant follow it and substitute the numbers from the OP's problem in for yourself you probably shouldnt be participating. Ill break it down for you tho anyway.

In the video:

48÷2(9+3)
48=a
2=b
9=c
3=d
a÷b(c+d)

now the OPs numbers...
6=a
2=b
1=c
2=d

6÷2(1+2)

Same concept, same process. Answer is 9

if that doesnt clear it up for ya then i dont know what to tell ya

Edit: and if you are referring to the other link, that was just to illustrate that multiplication and division are performed left to right at the same time... before any addition and subtraction

edit on 2-5-2011 by ASeeker343 because: clarification

holy cow you jump right into "i shouldn't be participating" ???
really? what youtube video? i didn't view any video ... i was responding to the nonsense spewing here.

i guess i may go looking for the video just so i can respond to whatever nonsense this is ... care to share which page i might find it?

as for the other link, i was referring to it because the rule changes when parenthesis appear ... left to right goes out the window as well as sequencing based on the location of the parenthesis ... basic algebra.
EX: if the only parenthesis indicate an addition problem, you will perform it before any other.
If the parenthesis indicate the multiplication of a root ... first, you must find the root, not do the multiplication.

yes, the problem is poorly written, however, As it is written, the answer is only "1".