48÷2(9+3) = ???

[AndrewBird]

I feel like this thread needs this:

[Danny]

[Dozyproductions]

from the physics forum:

288? Following PEMDAS, I get 2:

48÷2*(9+3) = 48÷2*(12) = 48÷24 = 2

The reason why some people are getting 288 is that they're forgetting that there's an invisible multiply sign in the expression.

Honestly though, if I ever saw this I would apply a facepalm. It's not good notation and like you're seeing, it's ambiguous without proper use of parentheses and will confuse people. It's better notation to say

oh and the right way.

[J3M93]

if we let x= 9+3 we get f(x)=48/2x

if you graph 48/2x and let x = 12 you get 2

[M42Power]

According to my current education, he is right. Multiplication has the priority

[reelizmpro]

from the physics forum:



oh and the right way.

That's not really the issue. There is a difference between parentheses and a simple multiplication sign. I would argue if it were a simple multiplication sign then order of operations dictates that you should divide (left to right) before multiply since they are equal, in which case you would get 288. 48/2*(9+3) = 48/2*12=288 But because only parentheses were used, you must operate inside and distribute into it. You cannot just pull the 2 away from (9+3) or (12) and divide into 48. Even though the operation inside the parentheses is completed, parentheses remain until multiplication occurs...THEN you can divide.

[mikeedler]

damn, my daughter is in 5th grade here in Germany and I was doing that crap with here a few months ago.....
have to admit though, I was a bit confused at first after all these years not doing much math, kids keep your brain in gear.

[J3M93]

That's not really the issue. There is a difference between parentheses and a simple multiplication sign. I would argue if it were a simple multiplication sign then order of operations dictates that you should divide (left to right) before multiply since they are equal, in which case you would get 288. 48/2*(9+3) = 48/2*12=288 But because only parentheses were used, you must operate inside and distribute into it. You cannot just pull the 2 away from (9+3) or (12) and divide into 48. Even though the operation inside the parentheses is completed, parentheses remain until multiplication occurs...THEN you can divide.

exactly!!, there is no multiplication sign, there is parenthesis however, which implies multiplication, but does not substitute for a multiplication sign

The answer is 2

[Dozyproductions]

exactly!!, there is no multiplication sign, there is parenthesis however, which implies multiplication, but does not substitute for a multiplication sign

The answer is 2

parenthesis does substitute for a multiplication sign. 2(9) = 18 just like 2x9 = 18. Distributive property.

[balooshinakus]

I am not sure how you guys learned math, but the answer is not 2. You are taking PEMDAS too literally.
PEMDAS =
1. Parens
2. Exponents
3. Multiply/Divide from left to right
4. Add/subtract from left to right


But the logic you are applying the answer to: 4 - 3 + 4 would be 4 - 7 = -3, the correct answer is 5.

In every programming language and calculus course I have taken the answer to the problem would be 288, and is completely unambiguous.

[frankenbeemer]

http://lmgtfy.com/?q=48%2F2(9+%2B+3)

[frankenbeemer]

How do you suggest it's properly written then? "÷" and "/" are the same thing, and correctly written out 48 is over the rest.

The division sign is not a vinculum.

[frankenbeemer]

According to my current education, he is right. Multiplication has the priority

Multiplication does not have precedence over division and addition does not have precedence over subtraction. They are equal, and are taken in left to right order.

[rwh11385]

I am not sure how you guys learned math, but the answer is not 2. You are taking PEMDAS too literally.
PEMDAS =
1. Parens
2. Exponents
3. Multiply/Divide from left to right
4. Add/subtract from left to right


But the logic you are applying the answer to: 4 - 3 + 4 would be 4 - 7 = -3, the correct answer is 5.

In every programming language and calculus course I have taken the answer to the problem would be 288, and is completely unambiguous.

Majority of these kids can't comprehend that #3 are on the same level and order depends on position left to right. Good example of why taking letters too literally has them confused.

288. Multiplication occurs outside the parentheses, not within. Follow that realization up with the fact that it goes divide then multiply... bingo.

Multiplication does not have precedence over division and addition does not have precedence over subtraction. They are equal, and are taken in left to right order.

Yes.

[dirty30]

I honestly didn't even know it was an equation when I read the thread title.