Question of 8 ÷ 2(2 + 2) Has Divided the Internet & Even Confused Your Maths Teacher

Here’s a simple maths question: what’s the answer to 8 ÷ 2(2 + 2)?

Did you get 1? Good for you.

Did you get 16? Good for you, too.

Oh, wait…how can such a simple question have two different answers?

And just like the colour of the dress and the shoes, this viral question has divided the Internet once again.

It All Started From a Tweet

About five days ago (29 July 2019), Twitter user @pjmdoll posted an almost innocuous question:

oomfies solve this pic.twitter.com/0RO5zTJjKk

— em ♥︎ (@pjmdolI) July 28, 2019

Seems easy enough until there were two answers that seem correct.

The first way to solve this:

 8 ÷ 2(2 + 2) = 8÷ 2(4) = 8 ÷ 8 = 1

And the second way is this:

8 ÷ 2(2 + 2) = 4(4) = 16

So, our maths teacher would have said that no matter what, we’ve to work on the brackets first before Multiplication and Division, and finally Addition and Subtraction. But what if it’s a 8 ÷ 2(4): should we do the ÷ first or the 2(4) first?

I don’t know about you, but I don’t remember my maths teacher teaching me this, and so, people tried it with their calculators instead.

Well, it turned out that the “correct” answer is actually 16.

Don’t believe me? Key in the question in Google and you’ll get 16. After all, experience would have told us that Google is more reliable than your teacher.

But why?

Here’s the reason.

PEMDAS

PEMDAS is an acronym to let us remember what to calculate first. This image would have explained everything to you.

(P.S. We Singaporeans like to use the word “bracket” instead of “parenthesis”, but it’s the same)

Now, here’s when you’ll get confused.

In 8 ÷ 2(2 + 2), if we follow the PEMDAS, we should do the (2+2) first, which would then be  8 ÷ 2(4).

If parenthesis comes first, shouldn’t we do 2(4) first, which will then come out to 8 ÷ 8, which comes to the answer of 1?

Well, here’s the thing: 2(4) actually means 2X4, right? What we learn is that we must do the calculation in the parentheses; but essentially, what it means is that it’s actually 8 ÷ 2 x (2 + 2).

Now, that’ll be easy:

8 ÷ 2 x (2 + 2) = 8 ÷ 2 x 4 = 4 x 4 = 16

In other words, the problem here is the 2(2+2); they should be looked at as 2 X (2+2) instead.

But why so chim?

People In the Past Didn’t Use ÷

You see, 100 years ago, people might have used / instead of ÷.

So, when it comes to 8 ÷ 2(4), it’ll look like 8/2(4).

And with /, we’ll come out with this instead.

notation y’all pic.twitter.com/yAMie100Hi

— maggie (@BatmanOfficial_) July 29, 2019

Geddit?

In fact, this viral maths question isn’t the first to divide the Internet; two years ago, the same equation with different numbers confused others as well, and someone explained the entire issue in an easy-to-understand YouTube video here:

The moral of the story?

Use a calculator for every calculation. #justsaying