Baffling Math Problem Dubbed 2021's Answer to Viral Blue or Gold Dress Saga

A seemingly simple math problem that produced markedly different answers on a calculator and a phone has left the internet stumped and sparked comparison with several notable viral debates.

The problem was shared to Reddit by SnufflesMcPieFace alongside the caption "Multiple choice?" The post presents a picture of the same sum as it appears separately on a Casio calculator and an unspecified smartphone.

The sum presented on both screens reads as: "6÷2(2+1)." However, while the Casio device calculates the answer to the equation as "1," on the phone screen the answer is given as "9."

It's a contrast that prompted several Redditors to draw parallels between the math problem and the 2015 furore surrounding the image of a dress that appeared black and blue to some and white and gold to others.

"Blue dress," frostywafflepancakes quipped. "White and gold," benchodde17 fired back. "Black and blue," Anlsrnvs countered.

For others commenting on the post, the two debating results were reminiscent of the 2018 discussion prompted by a short piece of audio in which a voice can be heard saying one of two words: yanny or laurel.

Referencing the viral debate, Known-Dream-9467 joked: "Hmmm, I hear Yanny," with Cool_Alternative_495 responding: "Laurel."

While the perceived differences in the way the dress appeared was attributed to the way the human brain perceives color and chromatic adaptation and the yanny/laurel phenomena was the result of an auditory illusion, things appeared a little less clear cut when it came to the math problem.

"The Casio is correct," onymousbousch wrote. "It's wrong," Noob-4899 replied. "No, the parenthesis come first," onymousbousch, "That includes the outer 2 as well."

"The one on the left is following PEMDAS. The phone isn't," FrustratedHornyGay commented, in reference to the acronym PEMDAS designed to help remember the order or operations in a math equation: parentheses, exponents, multiplication, division, addition, subtraction.

Yet still there was disagreement. Will12453 responded: "The one on the right [the phone] is right. It's PEMDAS or EPDMSA from left to right. So in this case it's 6 divided by 2 multiplied by 3."

EPDMSA changes the order to: exponents, parentheses, division, multiplication, subtraction, addition. Even so, some were not buying it. "The calculator is right," OrangeMonkey274 declared. "What are you talking about. The calculator is right?" a confused sounding Murky-Smoke438 asked.

The debate has continued to rage over some 4,500 comments, with people weighing in on both sides of the debate. Some even came up with entirely new answers.

"I'm so bad at math that I ended up at 6," DaddyKanesChain revealed, prompting yet more discussion around how they could have reached that number.

Ultimately it was another user, sadAli3456, who reached the most definitive conclusion, namely that both answers were right—but not in a good way.

"You're communicating mathematical steps that you want someone to do or see," they explained. "There's no 'right' or 'wrong' answer. There's just the mathematical steps that the writer wants you to follow. If they write bad steps or steps in a bad way, then the equation is garbage."

Newsweek has reached out to SnufflesMcPieFace for comment.

This isn't the first time a math equation of this kind has left the wider public stumped. In July 2019, another tricky sum left the internet divided.

The sum, which was presented as "8÷2(2+2)" was posted on Twitter by PJMDoll, with the post shared over 20,000 times on social media.

More recently, in April another basic algebra equation was posted online with users challenged to come up with "anything other than 7." The challenge proved tougher than first thought.

Another tricky math problem also ended up doing the rounds on TikTok earlier this year, where it quickly became apparent that hardly anyone was able to actually get the answer right.