Math poll.

[Corbi]

This is posted online and I cannot believe the answers people are posting. My old school math says 4 yet these people are coming up with 79 and 104.

[NorwichGrad]

Order of calculations:

multiply / divide

always take priority before

add / subtract

50 + 50 - 25 x 0 + 2 + 2 =

is the same as

50 + 50 - (25 x 0) + 2 + 2 =

50 + 50 - 0 + 2 + 2 =

100 + 4 = 104

[SuffolkPunch]

^ Yup

BIDMAS - brackets, indices, division, multiplicaiton, addition, subtraction.

[mtpockets]

104

[TolerantLactose]

Agree with above.

[Mark1T]

4

50 + 50 - 25 is just a distraction, as those numbers could be any number, because when you multiply any number by 0, the answer is 0.

So, 2 + 2 = 4

[Cass40]

104. I'm not gonna be even mad if I'm wrong as I suck at math..

[LWW]

Please Excuse My Dear Aunt Sally.

[ElrondHubbard]

Whoever answered 79 simply can't read. Whether you answer 4 or 104 depends on your interpretation of operator precedence. Classically, it's taught that multiplication takes precedence over addition and subtraction, so in an expression with both operators, the multiplication will be performed first.

The problem with using a calculator is that they don't all follow that rule. Some do and some don't, and with some it depends on the mode that they're in. According to the link above, Microsoft calculator will give 4 in standard mode and 104 in scientific or programmer mode. My kcalc program gives 104 in both modes.

So the water is muddied, which is why the question was posted online in the first place. It depends on whether you use standard rules of order of operations, or simple left to right evaluation.

For a more interesting problem, compare 4+1/2 to 4+1÷2.

Personally, if an equation is written out, I would prefer people use parentheses where appropriate just to remove any such ambiguities.

[ElrondHubbard]

Please Excuse My Dear Aunt Sally.

Technically, "Please Excuse Dear My Sally Aunt" is just as valid.

[ElrondHubbard]

^ Yup

BIDMAS - brackets, indices, division, multiplicaiton, addition, subtraction.

You're so British!

[x-trainer ben]

the key to all this from college math is what do you do first?
I recall what others have said above

104

[exyl]

This is posted online and I cannot believe the answers people are posting. My old school math says 4 yet these people are coming up with 79 and 104.

Use the order of operations

[Corbi]

I do it in the order that is there and the answer is 4, anything times 0 is 0. This other stuff like BIDMAS is the 1st I have ever heard of it.

[Mark1T]

I do it in the order that is there and the answer is 4, anything times 0 is 0. This other stuff like BIDMAS is the 1st I have ever heard of it.

I agree. The order is provided. It 'aint calculus.

[mtpockets]

the key to all this from college math is what do you do first?
I recall what others have said above

104

I learned this in grade 7 or 8 I think..

[LWW]

If the zero were a 1 in the problem, the answer would then be 79.

[bustasinclair]

(50 + 50) (-25 x 0) + (2 + 2) = 4

Because the minus sign in front of the 25 is not nice and centered like the other signs in the equation, it appears that the 25 is actually negative 25. Whomever put this together was trying to be purposefully deceiving. Therefore, I say it could be either 4 or 104. Shrugs

[LWW]

(50 + 50) (-25 x 0) + (2 + 2) = 4

Because the minus sign in front of the 25 is not nice and centered like the other signs in the equation, it appears that the 25 is actually negative 25. Whomever put this together was trying to be purposefully deceiving. Therefore, I say it could be either 4 or 104. Shrugs

Negative twenty-five x 0 = 0

[bustasinclair]

Negative twenty-five x 0 = 0

Umm, yes it is

[LWW]

Umm, yes it is

Because it's neutral the rest of the operation is 100 + 0 + 2 + 2 = 104

[deadwoodgregg]

The correct misc answer to any question involving numbers is tree-fiddy.

[SuffolkPunch]

By the way, computer languages agree with BIDMAS - you can have any length expression so it becomes more important (whereas an older calculator shows one step at a time).

Paste the above into python for example and you get 104

[bustasinclair]

Because it's neutral the rest of the operation is 100 + 0 + 2 + 2 = 104

Really not worth arguing about, but the way I drew it out, the answer is 4 because there is no sign between the 50+50 and the -25, so you would multiply.

(50 + 50) (-25 x 0) + (2 + 2) = 4

(100) * (0) = 0 + (2 + 2) = 4

[Jtbny]

104. Order of operations FTW!

[Mark1T]

Negative twenty-five x 0 = 0

Any number multiplied by 0 = 0. And, you are correct.

This is why 2 + 2 = 4

[ElrondHubbard]

By the way, computer languages agree with BIDMAS - you can have any length expression so it becomes more important (whereas an older calculator shows one step at a time).

Paste the above into python for example and you get 104

There are some computer languages, and some calculators, that do strict left to right evaluation. APL evaluates right to left. And there are other precedence standards that are inconsistent, according to Wikipedia. MATLAB and Wolfram Alpha evaluate certain types of expressions differently with respect to exponents.

The more I read about it, the more it looks like a big mess. It's a wonder we haven't lost more space probes that way!

[SuffolkPunch]

There are some computer languages, and some calculators, that do strict left to right evaluation. APL evaluates right to left. And there are other precedence standards that are inconsistent, according to Wikipedia. MATLAB and Wolfram Alpha evaluate certain types of expressions differently with respect to exponents.

The more I read about it, the more it looks like a big mess. It's a wonder we haven't lost more space probes that way!

If in doubt, I use braces liberally... been caught out too many times.

[ElrondHubbard]

If in doubt, I use braces liberally... been caught out too many times.

+1. That's really the only solution. I use them even if they're not technically required, because I want to make sure there's no ambiguity.

[OldFartTom]

^ Yup

BIDMAS - brackets, indices, division, multiplicaiton, addition, subtraction.

I thought it was BODMAS? What's this "I" thing. I've got some googling to do, yes I never paid full attention in maths! I still struggle with maths as an adult. (Although they set the bar a bit higher)