The internet is full with conundrums that have left many people perplexed and discussing the genuine answer. Just like the infamous blue and black outfit that swept social media and even experts off their feet, a viral maths conundrum has left workplaces and even scientists scratching their heads.
In 2019, a Twitter user uploaded a photo asking their followers to answer a mathematical issue – 8 ÷ 2(2 + 2) – which sparked a debate throughout social media platforms.
Editors of Popular Mechanics, a lifestyle magazine, were at odds over the iconic maths dilemma. Taking the conversation to their official workplace chatbox, the editors argued and decrypted the true answer to the query.
According to one of the editors, the practical method taught in elementary and high school was to utilise the popular rule “PEMDAS” or “Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction.” In this scenario, equations or problems should be answered in the order of the operations listed on the acronym – those in brackets first, then exponents, and so on, from left to right.
Solving 2 + 2 in the parentheses first yields 2, leaving 8 ÷ 2 x 4 as the answer. According to Mashup Math, the equation requires doing the leftmost operation first, which is 8 2, rather than 2 x 4. This is despite Multiplication taking precedence over Division.
The quotient would be 4, which gives us 4 x 4, for a product of 16. However, half of the people online disagree with this operation, including scientists who understand maths.
The other half of Popular Mechanics editors agreed that the answer is one. How did they get to this question? They too used the term “PEMDAS” but interpreted it differently.
They agreed that the 2+2 in the parenthesis should be answered first, but the sum should be viewed as a parenthesis – 8÷2(4). One of the editors pointed out that, according to the math class he took, a multiplication operation in parenthesis trumps division, whether it is on the left side of the equation.
As the subject drew the attention of the internet’s furious debate, mathematicians and physicists joined the fray. Mike Breen, the American Mathematical Society’s Public Awareness Officer, stated that 16 is the correct number based on the order of operations.
However, he agreed that the equation as written is “ambiguous” in nature.
“In maths, there are many ambiguities. Mathematicians strive to create rules as precise as possible. According to the exact order of operations, you’d get 16, but I wouldn’t strike someone on the wrist with a ruler if they said one,” he explained.
Despite Breen’s obvious answer, some individuals remain sceptical. The other half of the magazine editors sought the assistance of Physics Professor Rhett Allain of Southeastern Louisiana University, who they claimed had finally resolved the disagreement.
“This is a convention. We have norms for writing these things, just as we have for spelling them. Still, there are several conventions. Some spell it ‘grey’, while others spell it ‘grey.’ “We still understand what’s going on,” he explained.
However, for him, the question should have been stated correctly as 8/(2*(2+2)), yielding the quotient of 1.