What is 6 - 1 x 0 + 2 / 2 ? 17

[charliealphabravo]

OK, so my architect boss is trying to stump me with this one. He says he saw it on some discussion group that was saying that engineers are poor in math because they answer 7. That was my answer as well, and since I am an engineer I must ergo be bad at math.

I am pretty sure there is no planet where the answer to this is 5, but what do I know?

Discuss.

 

[structSU10]

PEMDAS... so unless there are parenthesis missing, 7 is what i get. The only way to get 5 i see is (6-1)*(0+(2/2)).

 

[dik]

It's the mathematical order of operations... which simplistically is as follows:

1. terms inside parentheses or brackets
2. exponents and roots
3. multiplication and division
4. addition and subtraction

Do your mulitplication first and end up with -0, then the division 2/2 = 1, and then you have a simple 6+1 = 7

Dik

 

[stevenal]

The question was asked in the spreadsheet forum. Microsoft says 7.

 

[cowski]

If you have excel on your computer, enter it as a formula and see what you get (the programmers and mathematicians at MS agree the correct answer is 7). If he disagrees, he should file a bug report with MS and any/every other calculation software (mathcad, maple, mathematica, etc).

www.nxjournaling.com

 

[cowski]

Anyone have a link to the original "discussion"? I'd love to see some of the logic (or lack thereof).

www.nxjournaling.com

 

[BigInch]

If you type that expression in Excel using Architectural font, the answer is 1.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[Denial]

What answer do you want?
If I apply the operations in left-to-right order, I get 1.
If I apply them right-to-left, I get 5.
If I also read the numbers right-to-left, I get -5.
If I apply the operations alphabetically, in English, I also get 5.
Spanish, anyone?.
Martian?

However if I use the long-established and universally-observed rules of (earth-bound) mathematics, I get the same as everyone else on this post (except BigInch's "architectural font", apparently). That's one of the beauties of mathematics, and allows it to be described as the universal language.

But only among those with rudimentary mathematical literacy.

 

[BigInch]

Spanish could be as high as 8.
The time between same days of one week to the next is often described as 8 days.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[IDS]

I haven't got Architectural font, but I think Wingdings 3 gives the most appropriate response.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[fel3]

The only unambiguous approach to this problem is to invoke the standard order of operations rules that dik posted. We all agree that this results in 7. Mathcad also agrees.

The architect is full of himself. In my experience, engineers are generally better at mathematics than everyone except mathematicians and probably physicists. I have worked with dozens of very smart architects and none of them have the math skills of a typical engineer, except for two who also have an engineering degree on top of their architecture degree.

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[msquared48]

Mathematics is supposed to be the universal language.

This string is universally confusing to me. My logic says 1.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[electricpete]

msquared - typical convention: Multiplication/subraction has higher precedence than addition.
6 - 1 x 0 + 2 / 2 = 6 - (1 x 0) + (2 / 2) = 6 - 0 + 1 = 7

I apologize if I missed the meaning of your post


=====================================
(2B)+(2B)' ?

 

[electricpete]

No coffee yet this morning...
meant to say "Multiplication/division has higher precedence than addition/subtraction"


=====================================
(2B)+(2B)' ?

 

[IRstuff]

There should be no confusion about this. Order of operations is mandatory, not optional. This is not right to left convention; this is not described as a processor stack operation. Left to right has lower precedence than PEMDAS.

This is a fundamental convention that all math programs and textbooks have to adhere to, minus signs in Excel not withstanding.

TTFN
faq731-376

 

[stevenal]

Left to right has lower precedence than PEMDAS

It would seem the PEMDAS acronym is the problem here, puting the A before the S. In fact, order of operations states these two operations are at the same level, and should be performed left to right.

http://www.facebook.com/permalink.php?story_fbid=462469820439436&id=119281798091575

PEMDAS as interpreted by some where addtion is performed before subtraction: 6-[(1*0)+(2/2)]=5

Actual order of operations performs left subtraction prior to the addition: [6-(1*0)]+(2/2)=7

 

[IRstuff]

"6-[(1*0)+(2/2)]=5"

PEMDAS cannot assume this first case, because there are NO PARENTHESES in the original statement; you cannot arbitrarily add parentheses where none were given. Any such "assumptions" are grossly incorrect.

TTFN
faq731-376

 

[rb1957]

i don't know about that ...

addition and subtraction are the same level operators, it doesn't matter which order that the sums are done in.
6-0 = 6, 6+1 = 7
-0+1 = 1, 6+1 = 7

i think to interpret 6-0+1 as 5 is Wrong, it implies brackets around 0+1 which would change the order of operations.

it is obvious (no?) that adding or subtracting zero has no effect on the result.

 

[handleman]

PEMDAS is an acronym to help remember a rule. It is not the rule itself, and is indeed an imperfect representation. PEMODAOS (Parens, Exp, Mult Or Div, Add Or Sub) is more correct but not as easy to remember.

There are lots of people out there who are just smart enough memorize acronyms, but completely incapable of really understanding the underlying concepts. Apparently, your architect fellow falls into that category.

-handleman, CSWP (The new, easy test)

 

[cowski]

The negative sign is a unary operator:
6 - 1 is shorthand for: 6 + (-1)
I think the problem is some people are trying to separate the negative sign from the 1 then reusing it (incorrectly) as a later operation.
6 - 1 * 0 + 2 / 2
1 * 0 = 0
6 - + 2 / 2 =
6 - 1 =
5

The negative sign stays with the 1
-1 * 0 = 0
6 + 2 / 2 =
6 + 1 =
7

www.nxjournaling.com