# This equation has 2 wildly different answers depending on what you learned in school, and it’s dividing the internet caption
Math is hard.
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Getty

• Twitter user @pjmdoll shared a math problem: 8 ÷ 2(2 + 2) = ?
• Some people got 16 as the answer, and some people got 1.
• The confusion has to do with the difference between modern and historic interpretations of the order of operations.
• The correct answer today is 16. An answer of 1 would have been correct 100 years ago.
• Visit INSIDER’s homepage for more stories.

Viral math equations have been known to divide people on the internet. Some problems are so mind-bogglingly hard that they seem impossible, even if they’re meant for elementary school students.

This latest viral problem shared by Twitter user @pjmdoll is one such equation.

The equation is: 8 ÷ 2(2 + 2) = ?

Here’s the correct way to solve 8 ÷ 2(2 + 2) = ?

First, add the numbers in the parentheses.

8 ÷ 2(4) = ?

Now, do the multiplication and division from right to left.

8 ÷ 2(4) = 4(4) = 16.

The confusion is caused by the difference between modern and historic interpretations of the order of operations, known as PEMDAS:

1. Parentheses
2. Exponents
3. Multiplication and Division (left to right)
4. Addition and Subtraction (left to right)

A similar math problem went viral in 2011, when people couldn’t agree on the answer to 48÷2(9+3). Presh Talwalker, the author of “The Joy of Game Theory: An Introduction to Strategic Thinking,” explained the controversy on his YouTube channel MindYourDecisions and in a post on his blog.

People who got the number 1 as the answer to this problem were using an outdated version of the order of operations, multiplying 2(4) first and then dividing 8 by 8, according to Talwalker. That answer would have been correct 100 years ago. But plugging the equation as is into a modern calculator results in an answer of 16. You have to add another set of parentheses to get an answer of 1. caption
People are getting different answers depending on how they apply the order of operations.
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Talia Lakritz/INSIDER

Talwalker explains that part of the confusion is also caused by how the division symbol is ambiguously set in the problem.

“Textbooks always have proper parentheses, or they explain what is to be divided,” he writes on his blog. “Because mathematical typesetting is much easier today, we almost never see ÷ as a symbol, and instead fractions are written with the numerator vertically above the denominator.”

You can watch Talwalker’s full explanation of that equation below.