It shouldn't surprise me..

[LazerFlash]

...but it's kind of interesting just how many people get this wrong - and then very vociferously defend their error.

Here is a link to the Facebook page where the debate is raging: https://www.facebook.com/photo.php?f...type=1&theater

What's your solution? Are you sure?

[cindylu]

Here's my answer: 288???

[Davdu]

Hint: Please Excuse My Dear Aunt Sara

[LazerFlash]

Hint: Please Excuse My Dear Aunt Sara

Go to the Facebook page; even using that mnemonic, people are getting it wrong. They make one critical mistake in its application...

[LFE]

2
I do not have a facebook account so I can not go there.

[Tony]

No Facebook account? That makes you highly suspicious.

“not having a Facebook account could be the first sign that you are a mass murderer.”

Beware, Tech Abandoners. People Without Facebook Accounts Are 'Suspicious.'

[LFE]

No Facebook account? That makes you highly suspicious.

“not having a Facebook account could be the first sign that you are a mass murderer.”

Beware, Tech Abandoners. People Without Facebook Accounts Are 'Suspicious.'

I never been on twitter either...
However on a positive note to most readers, I focus all my attention to folks that point out things like you just did :-)





4:52
Talking Heads - Psyco Killer - CBGBs

[grafxgirl]

The answer is 2. You should follow the order of operations for PEMDAS. Parenthesis, exponents, multiply, divide, add, then subtract.

[cindylu]

I thought I did. I'll do again using GG's instructions.

9+3 = 12
48/2 = 24
12x24 = 288

or . . .

9+3 = 12 x 2 = 24
48/24 = 2

is that the process??

[LazerFlash]

I thought I did. I'll do again using GG's instructions.

‎288 *is* the correct answer.

Since there are no exponents to deal with and we know to perform the operation inside the parens before anything else, resolve them out, giving this: 48÷2x12 When solved left-to-right, the answer is 288.

Since the confusing operation seems to be the division - which many people seem to think needs to be done *after* the multiplication - treat it instead as a multiplicative inverse. That makes the equation 48x½x12, which equals 288. Any questions?

[grafxgirl]

‎288 *is* the correct answer.

Since there are no exponents to deal with and we know to perform the operation inside the parens before anything else, resolve them out, giving this: 48÷2x12 When solved left-to-right, the answer is 288.

Since the confusing operation seems to be the division - which many people seem to think needs to be done *after* the multiplication - treat it instead as a multiplicative inverse. That makes the equation 48x½x12, which equals 288. Any questions?

If you come across a multiplication table not in parenthesis, you are supposed to put the parenthesis around it to group it together. So after adding 9 and 3 to get 12 it leaves you with 48 / 2 x 12. The next step is to group the 2 x 12 so your equation becomes 48 / (2 x 12). Which means you would do 2 x 12 = 24. This leaves you with 48 / 24 = 2. According to what I have found 2(12) is the same as this [2(12)] because the grouping of 2(12) is implied to mean the same thing as if there were brackets, which in turn makes 2(12) the hierarchy before the division sign. In order to do the process where division and multiplication are equal, and to solve the problem left to right, the problem should read this 48 / 2 x (9+3). If the problem were written this way then the answer would be 288. That little multiplication symbol makes a big difference.

I just took another college math course recently, and I also saw this procedure being taught in our schools while I was doing my classroom observations.

The explanation behind the whole left to right theory is because of calculators. Some calculators will solve a math equation automatically using the PEMDAS, others do not have that capability, so they just solve the problem as it is typed, which means the operator of the calculator is responsible for knowing the PEMDAS operation or something like that. At least that is what I have been reading online.

[cindylu]

GG - I'm returning to school (shepherd university, 27 aug) and I just may take remedial math next spring. I've always had a fear of math but I believe its a matter of understanding and knowing the rules.

So, what is the correct answer?? Why is Lazer saying 288?? HELP!

[grafxgirl]

GG - I'm returning to school (shepherd university, 27 aug) and I just may take remedial math next spring. I've always had a fear of math but I believe its a matter of understanding and knowing the rules.

So, what is the correct answer?? Why is Lazer saying 288?? HELP!

Don't worry. I still suck at math, and still have to refer to my notes regularly! LOL! I just edited my explanation above by adding more information. Maybe that new info I added will shed some light as to my reasoning behind the way I solved the problem.

[LazerFlash]

So, what is the correct answer?? Why is Lazer saying 288?? HELP!

I guess it depends upon whether you were taught to follow the practice of "multiplication by juxtaposition" or not. "Multiplication by juxtaposition" means that multiplication indicated by placement against parentheses or brackets is higher in priority than 'regular' multiplication, and needs to be resolved before other operations. Using this method results in the answer of "2" because it treats the "2(9+3)" part of the equation as "[2x(9+3)]".

It's important to note that not everyone with letters after their name agrees on this issue. Consider also the complication that different calculators and software will process this differently. I've been told that there is even some inconsistency within one specific name brand of calculators.

I suppose the "correct" answer is to be very careful of your parentheses, make sure that there are no implied brackets and if unsure, ask the creator of the equation how they expect you to resolve the equation.

[Tony]

Some calculators will solve a math equation automatically using the PEMDAS, others do not have that capability ...

Oh god you just reminded me of the early RPN (Reverse Polish Notation) calculators. Does anyone else remember those? It was amazing that you could carry a calculator with you (though they didn't yet fit in a pocket), but trying to do the simplest calculation required a college degree.

[derricksonb]

Matt Damon says the answer is 2.

[LFE]

Oh god you just reminded me of the early RPN (Reverse Polish Notation) calculators. Does anyone else remember those? It was amazing that you could carry a calculator with you (though they didn't yet fit in a pocket), but trying to do the simplest calculation required a college degree.

That's why I went TI over HP...
The Museum of HP Calculators

www.hpmuseum.org/
The Museum of HP Calculators displays and describes Hewlett-Packard calculators ... HP-91 Printing Scientific Calculator; HP-92 Printing Business/Financial ...

[Kensey]

We always learned that after reducing exponents and parentheses, you multiply and divide from left to right with equal priority, then add and subtract from left to right with equal priority. (No juxtaposition rule, and you do the operations in the order they come, not all of one type of operation first.)

So the way we learned math agrees with Lazer's answer of 288:

48 / 2(9+3)
48 / 2 * (12)
24 * 12
288