Can you solve 8÷2(2+2)

[JettaKnight]

As originally presented to the Internet (post 46 I believe), there appears to be spaces left and right of the ÷ symbol, and no space between the first 2 and parenthesis. If no space between, you complete the parenthetical first and the correct answer is 1. If you type the whole equation with no spaces, the answer is 16.

Simple, really, it's all about appearances. If I were more purdier, I could give a better answer.

.

Space don't mean ****.

 

[Snapdragon]

It's a trick, and the whole point of writing it that way is to just trip people up. No one, when figuring out an actual problem, would write it like that. Instead of 8/2, they would simply write 4. ORRRR

They would write (8 * (2+2))/2 As that is much more logical.

It's a gotcha question that has absolutely nothing to do with real life, or actual mathematics.

Just like 99% of all math problems, it was contrived to test your ability to apply the rules.

 

[snowdrifter]

It's a gotcha question that has absolutely nothing to do with real life, or actual mathematics.

Yeah, it's an interesting (fun?) exercise. Thinking about and researching the equation this morning has reminded me how much I've forgotten since high school.

Some good opinions and logic in the comments on this page:
https://www.askamathematician.com/2...-orders-of-operation-business/comment-page-2/

I can certainly see both viewpoints, but I guess I'm still in the camp that says the parentheses should be dealt with first. From one of the comments on the link above:

6 = 4+2 = 2(2+1). When we do math, we all know you have to use the WHOLE term, and not a portion of it, with an operator. Therefore, 2(2+1) is an entire term with a value of 6, and you cannot use a portion of it with another operator, such as doing the 6/2 =3, and them multiplying by (2+1). That is incorrect.
Therefore, 6÷2(2+1) = 6÷6 = 1.

I see the 2(2+2) as one term.

But if brain teasers like this can get people to discuss and learn, that's the real victory.

 

[2A_Tom]

Just like 99% of all math problems, it was contrived to test your ability to apply the rules.

^^^^THIS^^^^

It teaches you to think things through, but who am I to talk, I like word problems too.

 

[chezuki]

Also, it’s an “expression”, not an “equation”.

 

[2A_Tom]

 

[Hoosier Carry]

I see the 2(2+2) as one term.

That’s how I was taught to do it as well.

 

[ATOMonkey]

That’s how I was taught to do it as well.

That's not the correct term though. The correct term is 1/2 * (2+2), that is where they are tripping people up, because the syntax is weird.

If you distribute 1/2 * (2+2) you get (1+1), which is 2 times 8 is 16.

 

[Dead Duck]

I see the 2(2+2) as one term.

That’s how I was taught to do it as well.

That's the reason I got 1 also.
It wasn't to do what's IN the parentheses, it was to remove the parentheses. The only way to do that is to solve that part first.



Three Dog Night Knows...
[video=youtube;UiKcd7yPLdU]https://www.youtube.com/watch?v=UiKcd7yPLdU[/video]

 

[Alpo]

It's a mathematical contraction like "ain't".

Friends don't let friends do this.

 

[Snapdragon]

That's the reason I got 1 also.
It wasn't to do what's IN the parentheses, it was to remove the parentheses. The only way to do that is to solve that part first.



Three Dog Night Knows...

The only way you can solve something is if there is an equal sign in it, and there is not, so you are evaluating this expression.

Just because adding the 2+2 and then taking it times the 2 feels more natural to you, it doesn't make it correct.

 

[Dead Duck]

The only way you can solve something is if there is an equal sign in it, and there is not, so you are evaluating this expression.

Just because adding the 2+2 and then taking it times the 2 feels more natural to you, it doesn't make it correct.

Hey Man!
I was a Professor at two Universities and I stand by my answer.


















Granted, I taught Theatre but that shouldn't matter.

 

[2A_Tom]

Not a math Professor, gender studies or something similar, I'm guessing.

 

[JettaKnight]

Not a math Professor, gender studies or something similar, I'm guessing.

Not English writing, either.

 

[Hoosier Carry]

There is a difference between:

2 x (2+2)
and
2(2+2) when it comes to this equation

 

[Hornett]

There is a difference between:

2 x (2+2)
and
2(2+2) when it comes to this equation

No.
There is not.
The 'x' is implied and operations are left to right once the parenthesis are cleared.
Everything has rules, especially math.

 

[Snapdragon]

There is a difference between:

2 x (2+2)
and
2(2+2) when it comes to this equation

No, there is not. And for the umpteenth time (a mathematical term), it is not an equation. An equation has an equals sign with terms on both sides.

 

[eldirector]

Can someone please link to an authoritative source that says "implied" multiplication is different than explicit multiplication, and therefore an exception to PEMDAS?

Is there a PE {do whatever you want} MDAS rule we don't know about?

 

[chezuki]

No, there is not. And for the umpteenth time (a mathematical term), it is not an equation. An equation has an equals sign with terms on both sides.

I knew you’d enjoy this thread.

 

[Snapdragon]

Hey Man!
I was a Professor at two Universities and I stand by my answer.


Granted, I taught Theatre but that shouldn't matter.

Um, OK, "man". I was also. And I taught actual mathematics and algebra.