Often, social media has to be polarizing to be profitable, with people clashing and increasing engagement. Over the last few days, there has been a peculiar fight online – and it all has to do with a math equation.
The equation posted by @pjmolI appears to be simple and straightforward: 8 ÷ 2(2+2) = ? There are no weird operations or integer numbers, yet people are baffled when they solve the equation and get different answers from their peers, either 16 or 1.
Even different calculators produce different results. Some people are claiming math is broken or that nobody taught them maths properly. However, the confusion lies in the fact that the question is set up in a misleading way.
So what's the truth? According to the rules of algebra, the answer should be 16. Let’s break it down with the traditional approach. It doesn’t matter if you have been taught algebra with the BODMAS (brackets, order, division, multiplication, addition, subtraction) conventions or the PEMDAS (parentheses, indices, multiplication, division, addition, subtraction).
To begin, you solve the bracketed addition bit and end up with an equation that reads 8 ÷ 2 x 4 =? According to both BODMAS and PEMDAS, division and multiplication have the same priority. So once you get there, how should you solve it? From left to right. You do 8 divided by 2 and then you multiply by 4.
So why do people and calculators both get it wrong? The equation is set up to be ambiguous, and mathematicians would certainly be annoyed if you wrote it like that. For humans and machines, it literally depends on which direction you move after solving the brackets. People that calculated 1 shouldn’t feel like they have done an atrocious mistake.
What’s missing in the equation is a couple of brackets that would allow someone to arrive at the correct solution without ambiguity. You could have (8 ÷2)x(2+2), which would equal 16, or you could write it as 8÷[2x(2+2)], which equals 1. Both these options would certainly have been more straightforward, but they probably wouldn’t have gone viral.