Every so often, do you get lured in by those I.Q. tests you see on the internet? Come on, you can tell the truth. You wouldn’t be the first to drop what you’re doing at work to break out some scrap paper for a 7th grade level math problem.
Well, this is one of those times. Stop whatever you’ve got going on for a brain teaser. Grab a pencil (not a pen), a piece of paper, and leave your calculator off to the side. We don’t have a 30-question test for you, because this one math question is enough.
If you were (or are) the captain of your school’s Math League or PEMDAS cheer squad, then you’ll love this challenge. It’ll take you right back to junior high. Please, go ahead and try. We’ll wait.
Based on a Japanese study by university researchers, only about 60% of the engineers who attempted to solve the problem got the correct answer. Those thousand or so engineers were in their early twenties, so they were not that far removed from their early academic experiences. It was concluded that some of them didn’t have basic math skills.
Instinct will tell you to excuse your Aunt Sally, causing you to address that division sign in the middle first, then add, and finally subtract. If that’s your strategy, what did you get? Was it a negative answer? Or was it 9? No worries, this one is easy to get wrong.
The problem is using PEMDAS as a hard rule to solve the problem. Though this is the way we were taught as kids, it can be confusing when applying it to find the right answer. Why?
Because people forget about invisible parentheses and how to work from left to right. Some people believe that addition always comes before subtraction (A, S) or that multiplication comes before division (M,D) every time.
And how about those fractions? It’s helpful to remember the properties too: commutative, associative, and distributive. It’s tricky.
What you want to do here is start over by tackling 3 ÷ 1/3 first, and no, you’re not supposed to multiply here. Divide! Hint: 3 divided by 1/3 is actually 9. Take it from there. Using a calculator, it’s likely that it will read that relationship between 3 and 1/3 as a funky way to arrive at 1 before working out the rest of the equation. If you did that too, we understand how you arrived at your final answer.
Watch this entire video to see the correct answer, and if you still insist that it’s something different, feel free to engage in endless debates in your inner circle or with internet strangers. Trust us, these types of math problems are a hot topic.
Like mind-bending puzzles that ask you to spot the object, these types of tests are meant to be fun. Don’t let these questions invade your peaceful sleep at night or have you thinking you need a middle school refresher. Instead, let allow them to help you keep your mind sharp.
Did you get the right answer on the first try? Are you mathematically inclined? What are your thoughts on PEMDAS?