Who changed the definition of BODMAS?

19 December 2016.

By Geni Dee.

BODMAS is an acronym used in mathematics to explain the order of operations when solving an equation. It stands for Brackets, Order, Division, Multiplication, Addition and Subtraction.

Americans use something similar but call it PEMDAS (Parentheses, Exponents, Multiplication and Division, and Addition and Subtraction), meaning division and multiplication are ranked equally and addition and subtraction are ranked equally. Whichever one you refer to, the maths remains the same.

But apparently, over the last 15 years, the rules of mathematics have changed.

I recently stumbled upon a viral thread about an elementary maths problem that has sparked a heated debate on Facebook and YouTube. The question posed was simple… What is 6/2(1+2)?

Without a moment’s hesitation I answered 1 (only in my head, I am not one to comment on such threads). However, 9 out of 10 people seem to differ from me.

Most people believe the answer to be 9, which they reached by using BODMAS. Without going into too much detail, BODMAS deals first with what is inside the bracket and then left to right to solve the rest of the equation. The issue, however, comes with most people not recognising that the number 2 in front of the bracket should first be multiplied in before you can continue solving the equation.

If 9 is the answer on the internet, then it must be true (please take note of the sarcasm that is intended in that sentence). There are even “experts” on YouTube who have posted solutions to this problem and how to get 9 as an answer.

I was only comforted by the fact that most people in engineering, physics and maths, agreed with my answer. I even posed the question to all of my colleagues (who are engineers) and they also supported my reasoning. One YouTube user tried to explain the problem to the masses in words, “If you have 6 apples that you want to divide between two groups of 1 boy and 2 girls each, each person can’t get 9 apples!”

Mathematics is supposed to be a universal language so where does this ambiguity come from and who changed the rules of BODMAS? It seems that the culprit is the “smart” technology we carry around in our hands. If you enter the equation into your phone, you get an answer of 9. This is because the phone automatically changes the 2( to a 2x(. It looks like it should mean the same thing but it doesn’t.

Even faithful Google gives an answer of 9. In a time where we rely heavily on technology to provide us with all the answers, it seems logical that most people would accept the solutions without question.

It is somewhat alarming to think that many people take whatever is written on social media as the absolute truth without even giving it a second thought. People turn to Facebook for advice on everything from medical to personal issues. Fake news sites are shared without proper vetting of the information and have even been blamed for winning Trump the US election.

Usually, I find these things entertaining and I am always surprised about how creative people can be. I am, however, starting to question the common sense of some social media users if basic mathematics creates such discord.

I try to be open-minded, so if the way we analyse mathematics has really changed, will someone please let all the engineers know?! Because we are still using scientific calculators and the answer is 1.

Even if you disagree with me and still believe the answer is 9, I just hope that in future you will at least question things posted on social media before believing it blindly.