Quick maths puzzle splits web – and even calculators are getting it WRONG
A SIMPLE maths puzzle has got the internet up in arms, with amateur number crunchers battling over who's got the right answer.
The equation, "8÷2(2+2)=?", was posted to Twitter by an anonymous maths fan and has web dwellers divided over two solutions.
Some say the answer is 16, while others are certain the solution is 1.
User '' posted a picture of the equation over the weekend, urging their followers to "solve this".
It wasn't long before a war of words broke out.
"16. Some of ya'll failed math and it shows," quipped one enraged user.
Another said: "I have two math degrees it's 1."
The puzzle even saw people pull out their calculators in a bid to get to the bottom of the argument.
But even that didn't help. Some appeared to show the answer is 16, while others offered that 1 was the solution.
Speaking to The Sun, one mathematician revealed that the confusion arises because there are technically two ways to answer the question.
Dr Thomas House, a lecturer in Applied Mathematics at the University of Manchester, said it depends on how you use the equation's brackets.
What's the solution?
Here's how to work it out...
- There are two ways to solve the tricky equation "8÷2(2+2)=?"
- You can either end up with 1 or 16, and it largely depends on how you use the brackets
- One way involves taking 8 and diving it by 2x(2+2)
- That leaves us with 8÷2x4, or 8÷8 which is 1.
- The second way says that we take 8÷2 and multiply it by 2+2
- 8÷2 is 4, and 2+2 is 4, which leaves us with 4x4=16
- Speaking to The Sun, Dr Geoff Evatt, a lecturer in applied mathematics at the University of Manchester, said the way the original equation is written is what's confusing people
- "The question is ambiguous," he said. "Looks to me like an issue with where one should be placing brackets"
- "It's not 100% clear what operation the (2+2) is supposed to achieving from the way it is stated, presumably hence the debate"
- So, if they mean:
a) 8÷(2x(2+2)) then this equals 1.
but if they mean:
b) (8 ÷2)x(2+2) then this equals 16.
"The usual way to interpret the calculation is that anything within brackets comes first," Dr House told The Sun.
"So we have 8÷2(2+2) = 8÷2(4). Then division takes place before multiplication, so we have 4(4), which is 16."
However, looking at the brackets a different way gives you 1.
"If someone wants to give multiplication precedence over division, there’s nothing to stop them saying that 8/2(4) means 8/8 = 1," Dr House added.
So where does that leave us? The maths expert says when in doubt, trust your computer.
"Typing the ambiguous 8/2*(2+2) into my computer gives 16, the ‘standard’ interpretation."
The real problem stems from the fact that the equation is written in a confusing way.
On a computer, in order to avoid the confusion spawned by the Twitter puzzle, you'd add a couple extra symbols to make clear what you mean.
"The lesson is that we have to be careful about definitions," Dr House said.
"When writing computer code the first interpretation would normally be written (8/2)*(2+2) and the second 8/(2*(2+2)) to avoid any ambiguity."
The maths puzzle is far from the first viral snap to divide opinion on Twitter.
Back in 2015, users went mad over a dress that appeared to be both blue and gold.
And in 2018, a recording of someone speaking split the masses after users couldn't agree on whether they were hearing "yanny" or "lawrel".
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What do you think the answer is? Let us know in the comments!
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