Working out percentages can often be people’s Achilles Heel but a revelation made on Reddit about how to work them out quickly has rattled many people to their core. Let us explain.
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Reddit user u/wlwlvr posted that an easy percentage hack meant you could reverse numbers to figure out the more simpler of the equations.
“Percentages are reversible. 8% of 25 is the same as 25% of 8 and one of them is much easier to do in your head,” u/wlwlvr wrote.
The thread was then filled with surprised users wondering how they’d never been told of such a simple maths hack.
How does it work?
Let’s break down how this mystical new knowledge actually works. Working out a percentage usually involves a fairly simple equation. For example, if you want to figure out 5 per cent of 60, you’ll need to break it down like this:
0.05 x 60 = 3
To do it in your head, if you’re like me, you’ll probably figure out what one per cent is and then multiply it by the percentage you want to find:
0.01 (1%) x 60 = 0.6, 0.6 x 5 = 3 so therefore the answer is 3
With u/wlwlvr’s trick, however, you would instead figure out the alternative equation and see if that’s any easier.
0.05 (5%) x 60 = 0.6 (60%) x 5
In this case, it’s not really any easier than the original equation but in some cases, it definitely will be. The example the user provided highlights that:
0.25 (25%) x 8 = 0.08 (8%) x 25 = 2
So it might not actually save your life every day, but it’s bound to help you in some situations. It’s not magic, it’s maths.
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This story has been updated since its original publication.