48÷2(9+3) = ??

• 288

• Total voters
510

diredesire

Why solve half an equation out of context, then insert it back into another formula, this doesn't prove anything?

12 + 5 + 13 / 8 + 5 * 12

x = 5+13
x = 18
12 + x / 8 + 5 * 12

... hmmm....

aceX

Hall of Fame

Why solve half an equation out of context, then insert it back into another formula, this doesn't prove anything?

12 + 5 + 13 / 8 + 5 * 12

x = 5+13
x = 18
12 + x / 8 + 5 * 12

... hmmm....
It's quite common in university mathematics to solve parts of equations 'out of context'. I guess I've been out of school too long ^_^

Thanks,
aceX

Jaewonnie

Professional
I will say it again. That star makes no difference.
unfortunately, it did for my casio fx-300

krz

Professional
After Excel, Mathematica/Maple, Matlab, Python, TI-83, Google Calc, a Mathematician, a math Teacher, and every other math major here except breakpoint(who invented his own random rule) has said 288.

At some point you would think the computer programs and the people with actual, real credentials would be listened to.

And no taking a couple calc classes in college doesn't count.

lol !

olliess

Semi-Pro
After Excel, Mathematica/Maple, Matlab, Python, TI-83, Google Calc, a Mathematician, a math Teacher, and every other math major here except breakpoint(who invented his own random rule) has said 288.

At some point you would think the computer programs and the people with actual, real credentials would be listened to.

And no taking a couple calc classes in college doesn't count.
Calculators and programming languages are not references for math expressions. Neither Matlab nor Maple handle the implicit multiplication (Maple returns 24 and ignores the rest).

If you search Google you'll notice a funny thing -- discussions about this particular order of operations "ambiguity" crop up regularly over the years.

There are mathematicians in this thread?

Last edited:

BobFL

Hall of Fame
Do you have the slightest idea what you are talking about?

Photoshop

Professional
Do you have the slightest idea what you are talking about?
hei guyz am i doing this rite??

accidental

Hall of Fame
Right, they're not arbitrary. There are usually sensible reasons why one rule has been adopted over another. But in controversies like these, one ought to realize that it won't be settled necessarily by what makes the best sense to oneself. Others have made the ruling, (mathematical symbols are accepted internationally, btw).

Here's another troublemaker, let x = .999..., where the ellipses implies that the 9s go on forever. Did you know that x = 1? Anyway, that's what the establishment believes, if you don't like it, maybe you can change their minds, but until that happens x = 1 will give a correct answer on a test.
1/3 = 0.333...
2/3 = 0.666...
3/3 = 0.999...
3/3 = 1?

Claudius

Professional
Is it possible to eat 99.99.....% of a hamburger? No.

BobFL

Hall of Fame
Is it possible to eat 99.99.....% of a hamburger? No.
Me in 'Five Guys'? That's easy 'no'!

F-T-S

Rookie
Is it possible to eat 99.99.....% of a hamburger? No.
I ate just one Lay's potato chip. Anything is possible.

tennisnoob3

Professional
But what's inside the parentheses is in the denominator, not the numerator.

48/2(12) = 2

(48/2)(12) or (48/2)12 = 288

Thus, the way it's written, the answer is 2.

(Note: I have scored in the Top 1% or 2% in the country in every standardized math test I have ever taken, and have engineering and MBA degrees from Ivy universities.)
i highly doubt that. did you go to standford too? :roll:

MegacedU

Professional
You have to distribute the two first. 2x9 is 18 and 2x3 is 6. 18+6=24. 48/24 = 2. I just got home from the club, and I had 3 vodka sprites. Winning!

F-T-S

Rookie
No, I'm afraid not. The order is left to right, so division comes first.

aceX

Hall of Fame
Do you have the slightest idea what you are talking about?
Yup, do you need me to explain what I did?

Leelord337

Hall of Fame
48÷2(9+3) = using PEMDAS

parentheses: 9+3= 12... then multiply so thats 2x12 = 24, then divide 48/24 thats 2

dr325i

G.O.A.T.
You have to distribute the two first. 2x9 is 18 and 2x3 is 6. 18+6=24. 48/24 = 2. I just got home from the club, and I had 3 vodka sprites. Winning!
FAIL...
Unbelievable how many College grads (or near to be the grad) do not know the 3rd grade math...
Sad, but true in our society...

dr325i

G.O.A.T.
48÷2(9+3) = using PEMDAS

parentheses: 9+3= 12... then multiply so thats 2x12 = 24, then divide 48/24 thats 2
WHY Multiply first???
Multiply has no priority over division...
Parentheses first.
48/2(9+3) = 48 / 2 * 12 = (left to right) 24 * 12 = 288

End of the story...

dr325i

G.O.A.T.
Yup, do you need me to explain what I did?
Please do so, so you can understand that it makes NO sense
Why didn't you assign x=48/2???
You are changing the meaning of the original statement...

MegacedU

Professional
It's distribution brah!

OHAI

Rookie
WHY Multiply first???
Multiply has no priority over division...
Parentheses first.
48/2(9+3) = 48 / 2 * 12 = (left to right) 24 * 12 = 288

End of the story...
Because if you are taught PEMDAS

Parenthesis
Exponents
MULTIPLICATION
division (notice how it comes after multiplication)
Subtraction

I'm no longer saying it's the correct way but that's the reason WHY.

MegacedU

Professional
FAIL...
Unbelievable how many College grads (or near to be the grad) do not know the 3rd grade math...
Sad, but true in our society...
The only FAIL here is you, because you're so damn upset over an internet forum. I didn't go to college, so fail x 10.

aceX

Hall of Fame
Please do so, so you can understand that it makes NO sense
Why didn't you assign x=48/2???
You are changing the meaning of the original statement...
In elementary mathematics, a term is either a single number or variable, or the product of several numbers or variables separated from another term by a + or - sign in an overall expression. For example, in

3 + 4x + 5yzw

3, 4x, and 5yzw are all terms.

dr325i

G.O.A.T.
Because if you are taught PEMDAS

Parenthesis
Exponents
MULTIPLICATION
division (notice how it comes after multiplication)
Subtraction

I'm no longer saying it's the correct way but that's the reason WHY.
YOU are taught WRONG.
Multiplication has NO priority over division, same for addition/subtraction.
However, multiplication and division have priority over the addition and subtraction.
Parenthesis first.

You do not understand what they taught you or they did it wrong.

Believe me, I learned where math was invented.

This is a 8-year-old math people!

dr325i

G.O.A.T.
In elementary mathematics, a term is either a single number or variable, or the product of several numbers or variables separated from another term by a + or - sign in an overall expression. For example, in

3 + 4x + 5yzw

3, 4x, and 5yzw are all terms.
what??????

MegacedU

Professional
what??????
Don't you guys have some Love Parade where you are? Sounds hypocritical to me!

dr325i

G.O.A.T.
The only FAIL here is you, because you're so damn upset over an internet forum. I didn't go to college, so fail x 10.
Obviously you did not do anything with psychology...
How did you get the idea that I am "SO DAMN UPSET"???
I am drinking my morning coffee and replying to people (like you) that do not know the basics...
You should be the one upset, talking on the tennis forum instead of "learning to walk"...

BobFL

Hall of Fame
Yup, do you need me to explain what I did?
Yes but do not explain what you did. Explain why you did it. Put it in context with a given equation.

MegacedU

Professional
How 'bout this one: Tdub+Megacedu^tipsy = ???

ans:
L-O-V-E

F-T-S

Rookie
A common technique for remembering the order of operations is the abbreviation "PEMDAS", which is turned into the phrase "Please Excuse My Dear Aunt Sally". It stands for "Parentheses, Exponents, Multiplication and Division, and Addition and Subtraction". This tells you the ranks of the operations: Parentheses outrank exponents, which outrank multiplication and division (but multiplication and division are at the same rank), and these two outrank addition and subtraction (which are together on the bottom rank). When you have a bunch of operations of the same rank, you just operate from left to right. For instance, 15 ÷ 3 × 4 is not 15 ÷ 12, but is rather 5 × 4, because, going from left to right, you get to the division first. If you're not sure of this, test it in your calculator, which has been programmed with the Order of Operations hierarchy.
http://www.purplemath.com/modules/orderops.htm

dr325i

G.O.A.T.
How 'bout this one: Tdub+Megacedu^tipsy = ???

ans:
L-O-V-E
Much better

MegacedU

Professional
I analyze financial statements and make a comfortable living while I wait to earn my law degree. Teehee.

OHAI

Rookie
YOU are taught WRONG.
Multiplication has NO priority over division, same for addition/subtraction.
However, multiplication and division have priority over the addition and subtraction.
Parenthesis first.

You do not understand what they taught you or they did it wrong.

Believe me, I learned where math was invented.

This is a 8-year-old math people!
You're not understanding. An OPEN minded person wouldn't close people off because they were wrong but instead explain to them why they were wrong so in the future they wouldn't make the same mistake. But instead you're being a ****** and calling everyone retards because they were taught incorrectly.

MegacedU

Professional
Because of you, I will skip the Czech Republic on my tour of Europe.

dr325i

G.O.A.T.
I analyze financial statements and make a comfortable living while I wait to earn my law degree. Teehee.
So, you are going to College...
Law degree...wow, impressive, how did you pass the LSAT "games" section, it does include the basic math (from someone who scored 169 in 2003)

dr325i

G.O.A.T.
Because of you, I will skip the Czech Republic on my tour of Europe.
I am an American, so skip the US, too

And stay away from the Law because your logic is....blah...

MegacedU

Professional
So, you are going to College...
Law degree...wow, impressive, how did you pass the LSAT "games" section, it does include the basic math (from someone who scored 169 in 2003)
I don't remember anyone asking you.

dr325i

G.O.A.T.
You're not understanding. An OPEN minded person wouldn't close people off because they were wrong but instead explain to them why they were wrong so in the future they wouldn't make the same mistake. But instead you're being a ****** and calling everyone retards because they were taught incorrectly.
Sorry if I left that impression however, I never called anyone a ****** in this thread...
I called it a failed math education rather than a retardation...

I do hope, though, that you learned something from this thread.

BreakPoint

Bionic Poster
The by hand rules are the same as computer rules...
The format used to program a computer to solve equations is not the same as writing out the equation in a format to be solved by hand.

BTW, if the 12 was supposed to be in the numerator, the equation would have been written:

48(9+3)÷2 or 48(9+3)/2

The fact that the equation was written:

48÷2(9+3) which is the same as 48/2(9+3) means that the (9+3) or (12) is in the denominator.

Numbers or variables to the left of the / are in the numerator and numbers or variables to the right of the / are in the denominator. Why? Because using the forward slash / symbol is how people type out the divide by line using a keyboard because they can't easily type out a horizontal line and put numbers and variables above the line for the numerator and numbers and variables below the line for the denominator. Thus, the / sign is used for convenience, with the numerator to the left of the / and the denominator to the right of the /.

BobFL

Hall of Fame
The format used to program a computer to solve equations is not the same as writing out the equation in a format to be solved by hand.

BTW, if the 12 was supposed to be in the numerator, the equation would have been written:

48(9+3)÷2 or 48(9+3)/2

The fact that the equation was written:

48÷2(9+3) which is the same as 48/2(9+3) means that the (9+3) or (12) is in the denominator.

Numbers or variables to the left of the / are in the numerator and numbers or variables to the right of the / are in the denominator. Why? Because using the forward slash / symbol is how people type out the divide by line using a keyboard because they can't easily type out a horizontal line and put numbers and variables above the line for the numerator and numbers and variables below the line for the denominator. Thus, the / sign is used for convenience, with the numerator to the left of the / and the denominator to the right of the /.

Photoshop

Professional
question for those saying 2 is the correct answer.

48÷(9+3)2 = ??

Is the answer 8 or 2?

OHAI

Rookie
question for those saying 2 is the correct answer.

48÷(9+3)2 = ??

Is the answer 8 or 2?
I'm curious to why you chose to use blue for eight and red for two?

Is this to throw people off?

Are people more inclined to choose red over blue?

BreakPoint

Bionic Poster
No it can't. It can quite obviously mean 48/2*12

Surely, using your own logic, if the 12 was the denominator, it should be written like:

48/(2(9+3))

to make it clearer.
Actually, if you want 12 in the denominator. You do this:

48/(2*12)
And if you want the 12 in the numerator, the equation would have been written this way:

48(9+3)/2 or 48(12)/2

The 12 would have been to the left of the /. But since the 12 is to the right of the /, it's in the denominator. That's why the equation was written as: 48/2(9+3) and NOT 48(9+3)/2

Photoshop

Professional
I'm curious to why you chose to use blue for eight and red for two?

Is this to throw people off?

Are people more inclined to choose red over blue?

This should help people pick the right answer.

aceX

Hall of Fame
And if you want the 12 in the numerator, the equation would have been written this way:

48(9+3)/2 or 48(12)/2

The 12 would have been to the left of the /. But since the 12 is to the right of the /, it's in the denominator. That's why the equation was written as: 48/2(9+3) and NOT 48(9+3)/2
Good to see some people stop and think rather than blindly following rules they learned in school.