Seemingly Simple Math

What is the answer to this math problem:

8 ÷ 2 (2 + 2)

16 or 1, depending.

According to PEMDAS, parentheses come first: 8 ÷ 2 (4)

Then, even though multiplication is first in PEMDAS, you go left to right: 4 (4) = 16

If you got 1, you’re in good company. That’s what I got at first too but most calculators I’ve tried get 16.

I found this at Popular Mechanics and the debate continues online.

Posted in Brain Teasers

 

5 Comments on "Seemingly Simple Math"


Mark W says
September 1, 2019 @ 22:43

Hi Dan,

Like you, I arrived at the answer: 1.

Simply because to equal 16, I believe the equation would have to be set out as:
(8 ÷ 2) (2 + 2) ?

Love your puzzles, thanks!


Will J says
September 30, 2019 @ 13:58

I don’t know how you come up with 1….I get 16 all day
8÷2(2+2)=
8÷2(4)=
4(4)=
4*4=
16


Wyatt A. Johnson says
February 9, 2021 @ 16:12

Here is how people get 1, also I believe you get 16 through a contradiction, and the divided sign is a trick.

8/2(2+2) can be interpreted as 8/(2(2+2)) or (8/2)(2+2).
Here is how I would do it:
8/2(2+2)
8/2(4)
8/8 <—- I evaluated the value with the parenthesis
1
but this would assume that the fraction is 8/(2(2+2)) when it could easily be (8/2)(2+2) so the basis of the riddle is upon an uncertainty that you cannot fix through plantext.


qwrty says
March 4, 2021 @ 02:25

R you kidding? I got 4!!!


turtle says
September 4, 2021 @ 00:58

8w ÷ 2 (2w+2w) would be = 1 …. not 16w^2

Put me down for 1


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