Current Events > CE please help .... 8 ÷ 2(2 + 2) = ?

(+) Yeah! (+)

iFuzedDaHostage posted...

What is

8
----------
2(2+2)

?????

That is equal to 1. Unlike the original problem, where the 2(2+2) is not grouped together

iFuzedDaHostage posted...

The calculator determines that because it was determined to do it as

BECAUSE THAT'S WHAT IT WAS WRITTEN AS. The calculator is programmed to follow the order of operations. If you want a different result, write a different expression.

Mathematics has rules and conventions that you have to abide by. If the person wants it to be interpreted differently, then the person has to write the expression differently.

Like, if I tell you that the food is really delicious, then I'm conveying a meaning. If my actual intent is to convey that the food is so disgusting that I want to cry, then I cannot use the word "delicious".

iFuzedDaHostage posted...

The correct answer is whoever wrote the question needs to explain what he means and rewrite the fucking question.

No. The correct answer is 16, and those who cannot recognize that need to ask their elementary schools for a refund.

iFuzedDaHostage posted...

What is

8
----------
2(2+2)

?????

That's not relevant because that's not what the written expression indicates.

If you write the expression 8 + 4 * 2, the answer is 16. If you had written (8+4) * 2, the answer would be 24, but that's not what you wrote, so you can't say, "Well maybe he meant to write...", because the fact is, that's not what was written. You need to evaluate the problem on the page. Not your fantasy interpretation of what the problem is.

Sariana21 posted...

I KNOW what the rule is, and what the correct answer is. I also know it is not as clear and straightforward as some of you are saying.

The thing is, it *is* clear. It is only unclear if you are insistent on using that stupid acronym PEMDAS, which is a very misleading acronym that doesn't actually convey the order of operations accurately. For example, there is no hard and fast rule saying that you have to perform the operations inside the parentheses first...and in this case, there's no hard and fast rule saying you even have to evaluate the operations inside the parentheses at all! This is only misleading if you have a flawed understanding of mathematics.

Sariana21 posted...

Autistic people, for example, tend to be rule followers, but many of them also are very, very logical. This kind of crap would drive some of them nuts. And anyone else who just sees things differently. And possibly a student from another country (Im still not sure about how international PEMDAS is).

Students with autism likely would not find this to be a problem, because they are generally very rigid in what they do, and thus would not be thrown off by something clearly intended to mislead people who misuse acronyms like "PEMDAS". Students from other countries? Other countries do a much better job of actually teaching mathematics for understanding, whereas we here still use stupid acronyms like "PEMDAS" and think that constitutes mathematical understanding. I've met MATH TEACHERS who claim that "multiplication comes before division".

Sariana21 posted...

As for the -2^2 question, the ambiguity there results from the fact that we use the same symbol for both minus and negative even though they are not the same thing.

There is no ambiguity there. The exponent comes before the negation. Therefore, the answer is -4. If you wish to square -2, then you must write it as (-2)^2. Even if it were a "minus" sign, you're still "minusing" 2^2, and thus the answer would still be -4.

Mathematics has a precise order in which things have to occur for this very reason. "Well, it could be..."

No it can't. It can only be what's written on the page. If you're interpreting it a different way, that's because you're reading a problem that's not there. You're answering your own made-up imaginary question, not the question that's on the page.

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8 2(2+2)=?
82(2+2)-?=0
82(4)-?=0
2(4)-?=-8
8-?=-8
-?=-1

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I can never tell if people who defend the wrong answer in these topics are trolling or serious.

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Turbam posted...

8-?=-8
-?=-1

8 - 1 = -8?

Try again with ? = 16. Also don't try and complicate the math so much.

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Turbam posted...

8 2(2+2)=?
82(2+2)-?=0
82(4)-?=0
2(4)-?=-8
8-?=-8
-?=-1

In your third line, you subtracted 8 from both ides of the equation. Not how math works since that 8 is dividing the 2

As an example:

102 = 5
However, you cannot subtract 10 from both sides to claim that
2 = -5

Since that's after all, obviously not true

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You all will be happy to know that my (autistic) 16-year-old rising junior knew exactly how to solve both of your problems.

He did did point out, though, that no one would ever use that division sign in a real math problem.

:-)

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Does using a suddenly impede your ability to solve simple math problems? By definition, it simply means divide. There isn't some magical phenomenon that happens that somehow distorts the basic laws of math because you used an unpopular symbol.

Also stop hiding behind autism. Autism has nothing to do with a person's ability to solve simple math problems


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/ and x left to right. Pemdasd

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Android calculator says 16, Mathway says 1. In problems with division, it is written like a fraction at the moment of division.

So really, it should be as 8/2(2+2). Which will in no way, shape, or form ever be 16.

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Please
Excuse
My
Dear
Aunt
Sally

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GEMDAS>PEMDAS

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Officially it's 16 but the way you write it and not expect people to get confused and get 1 you'd get slapped and sent back to do your common core.

What you do is paste it into google and then vote.

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Also order of operations is not some sort of law of mathematics (there is such a thing in logic and algebra, therefore programming, etc, but not for this kid stuff). It's a convention precisely to avoid this sort of silliness.

SamsungGearS2 posted...

Please
Excuse
My
Dear
Aunt
Sally

Please Excuse
My Dear
Aunt Sally

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According to my college level algebra class, it would be 1. Don't know (or care) how common core is teaching these days.

16

PEMDAS has a stipulation to it: Multiplication and division are on the same level, whichever comes first left-to-right. This goes for addition and subtraction as well.

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It is strange to me that some people take the MD part of PEMDAS as a hard rule that multiplication has to come before division, while simultaneously understanding that AS are on the same level.

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The correct answer is TC gets a boot to the head.

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The amount of people getting confused by such basic mathematics make me weep.

8 2(2 + 2) = ?
is exactly the same as
8 2 * (2 + 2) = ?

Being next to parenthesis does not give it higher priority so you still go left to right.

KyerWiz posted...

The amount of people getting confused by such basic mathematics make me weep.

8 2(2 + 2) = ?
is exactly the same as
8 2 * (2 + 2) = ?

Being next to parenthesis does not give it higher priority so you still go left to right.

That's not why people are doing it wrong. They're doing it wrong because it was taught to them wrong. It was taught wrong to me too. The way I learned it was multiplication is done before division, addition is done before subtraction, etc. This is why, when these topics are made or any time it makes the rounds on facebook, a lot of people get it wrong. It's because of poor teachers and the poor education system in the US.

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6x(x + 5y) is the same thing as 6x + 30xy.

But due to the nature of shorthand, that's usually a different expression than 6 * x(x + 5y). No one goes out of their way to go 6 * x(x + 5y) unless they were intentionally communicating poorly and then acting smug when they're misunderstood.
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philsov posted...

6x(x + 5y) is the same thing as 6x + 30xy.

But due to the nature of shorthand, that's usually a different expression than 6 * x(x + 5y). No one goes out of their way to go 6 * x(x + 5y) unless they were intentionally communicating poorly and then acting smug when they're misunderstood.

12 6x(x + 5y) would be 2x(x + 5y)
which is different from 12 (6x(x + 5y))

Obviously, anyone writing it like this is actively trying to confuse people.

thrashmetal14 posted...

According to my college level algebra class, it would be 1. Don't know (or care) how common core is teaching these days.

Ask for a refund.

Ryan__Leaf posted...

16

PEMDAS has a stipulation to it: Multiplication and division are on the same level, whichever comes first left-to-right. This goes for addition and subtraction as well.

The reality is that division is inverse multiplication, and so this idea that multiplication and division are different operations is, in itself, much of a misconception, because the reality is that division IS multiplication, so doing multiplication *before* division doesn't really make sense. Of course, you have to actually know math to do it, which is a problem.

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If it was written as (82) (2+2), it would be 16, but it's not. Therefore, the expression is understood to be 8/2(2+2)

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Perascamin posted...

If it was written as (82) (2+2), it would be 16, but it's not. Therefore, the expression is understood to be 8/2(2+2)

Which is still 16

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I got 16. You take care of the brackets first right?

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SSj4Wingzero posted...

Which is still 16

No? That works out to 1.

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Perascamin posted...

No? That works out to 1.

8/2(2+2) = 8 / 2 * (2 + 2).

This equals 16.

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Yo I keep getting 7

WTF!!!

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ZeroX91 posted...

82(2+2)
82(4)
88
1

This and if this isn't right well then black is east and white is west and my world is upside down

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BudDupree48 posted...

This and if this isn't right well then black is east and white is west and my world is upside down

lol this is wrong

82(2+2)
82(4) <---------------- division before multiplication
4(4)
16

Why are there 3 pages for this topic?
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Austin_Era_II posted...

Yo I keep getting 7

WTF!!!

Head to Vegas.

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DoGCyN posted...

8/2(2+2) = 8 / 2 * (2 + 2).

This equals 16.

Yeah so anytime you see a / , everything before the / becomes a numerator, and everything after becomes the denominator unless otherwise specified through the use of parenthesis or brackets.

So because it's not indicated that there are parenthesis before the division, the problem will look like this:

8
--------- = 1
2(2+2)

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BODMAS > PEMDAS

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Perascamin posted...

DoGCyN posted...

8/2(2+2) = 8 / 2 * (2 + 2).

This equals 16.

Yeah so anytime you see a / , everything before the / becomes a numerator, and everything after becomes the denominator unless otherwise specified through the use of parenthesis or brackets.

So because it's not indicated that there are parenthesis before the division, the problem will look like this:

8
--------- = 1
2(2+2)

False. There is no distinction between / and in mathematical equations. / is only commonly used due to ease in writing as well being readily accessible on keyboards. All multiplication and division takes place from left to right per the standard PEMDAS/BODMAS convention, no exceptions.
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Paragon21XX posted...

False. There is no distinction between / and in mathematical equations. / is only commonly used due to ease in writing as well being readily accessible on keyboards. All multiplication and division takes place from left to right per the standard PEMDAS/BODMAS convention, no exceptions.

This simply isnt true. A simple Google search will show you that this issue remains controversial.

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The confusion is with the parenthesis after the 2+2 is already added and therefore it reads 2(4). This is the same as 2 * 4. The fact that the 4 is in parantheses at this point is irrelevant because the multiplication symbol is technically not inside the parantheses. Therefore, 2(4) does not take priority over 8/2. So you're supposed to divide 8 by 2 first, which gives you 4, and then you're left with 4(4), which is 16.

Perascamin posted...

Yeah so anytime you see a / , everything before the / becomes a numerator, and everything after becomes the denominator unless otherwise specified through the use of parenthesis or brackets.

So because it's not indicated that there are parenthesis before the division, the problem will look like this:

8
--------- = 1
2(2+2)

What is 8/2+(2+2)?

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Sariana21 posted...

Paragon21XX posted...

False. There is no distinction between / and in mathematical equations. / is only commonly used due to ease in writing as well being readily accessible on keyboards. All multiplication and division takes place from left to right per the standard PEMDAS/BODMAS convention, no exceptions.

This simply isnt true. A simple Google search will show you that this issue remains controversial.

Only because of people perpetually stuck Dunning-Kruger Hill.
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Perascamin posted...

No? That works out to 1.

Only if you follow the rules of mathematics incorrectly and assume that / means "group everything after this symbol", which it does not and never has. Try typing it into some online calculator and see what you get

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SamWincester posted...

Why are there 3 pages for this topic?

cause people don't know simple math.


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Lol, now let's debate the Oxford comma!

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AssultTank posted...

So... if we distribute the 2 across the parentheses like people want, we get the following sequence...

82(2+2)
8(2+2)+(2+2)
84+4
2+4
6

Wait...wouldn't it be

8 / 2(2+2)
8 / 1(4+4)
8 / 1(8)
8(8)
64

answer is 16 but lolz at this

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AssultTank posted...

So... if we distribute the 2 across the parentheses like people want, we get the following sequence...

82(2+2)
8(2+2)+(2+2)
84+4
2+4
6

Of course the actual correct answer is 16, but hey...

You didn't distribute correctly. It would be (2x2) + (2x2)--which doesn't matter with 2s, of course.

The idea is that the 2(2+2) is a single unit and remains so. It becomes (2x2)+(2x2)=8. Turning it into 4+4 and then pulling out the first 4 (to divide it into the 8) wouldn't make sense.

Again, I know that's not how it works. The point is that it could. Someone made up a rule in the 1600s (apparently), but it has not always been followed the exact same way.

That we have computers that need to be programmed today likely has contributed to the standardization of the "rule." But based on my reading, there still is no consensus on the -2^2 issue. Some programs calculate it one way; some do it the other way.

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DoGCyN posted...

Wait...wouldn't it be

8 / 2(2+2)
8 / 1(4+4)
8 / 1(8)
8(8)
64

answer is 16 but lolz at this

How does 8/1(8) turn into 8(8)? I know you were making a joke, but none of the discussion involved arbitrarily changing out division for multiplication.


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