People are just discovering easy hack to solve percentages in seconds

Percentages don’t need to be a headache to solve if you know the right tricks.

Many of us hated maths at school, and if you’re not in a job that requires you to use the quadratic formula or calculate the area of a triangle, then you might be thinking that your GCSE maths exam taught you nothing that you use daily.

As much as we might hate to admit it, however, there are some areas of maths that we do use pretty often. One of those is percentages.

If you’ve ever been to a shop that’s offering a percentage discount, it can sometimes take a while to work out how much your goods are actually going to cost.

But there is an easy way to work out potentially puzzling percentages in mere seconds without a calculator.

In a video shared on TikTok by maths teacher Sarah Nichols, she revealed that percentages are reversible – which could be a total game-changer for both school kids and adults who need a helping hand.

What this means is that when you’re faced with a tricky percentage such as 4% of 75, you can flip it around to make it easier to solve. Working out 4% of 75 off the top of your head is almost impossible for the average person, but what about 75% of 4?

Solving 75% is simple, as you only need to know what half of the number and a quarter of the number are, and then add them together. In this example, half of four is two and a quarter is one, so 75% is three. And, by extension, 4% of 75 is also three.

Using another example of calculating 18% of 50, Sarah revealed: “Multiplication is reversible, and remember that the word ‘of’ means multiply. Two times three is the same as three times two, so 18% of 50 is the same as 50% of 18. 50% of 18 is way easier to figure out, because half of 18 is nine. 50% of 18 is nine, 18% of 50 is nine.”

So, when you’re eyeing a £50 jacket with a tempting 30% discount in a store, there’s no need for stress. Simply work out 50% of 30, which is 15, and subtract it from the jacket’s price – voila, you’ve snagged it for just £35.

The video left commenters astounded by the simplicity of the trick, with many disappointed they hadn’t known about it sooner – as it would have been a game-changer during their GCSEs.

One person exclaimed: “Why doesn’t school teach this ALL. THE. TIME? This is actually useful in life.”

Meanwhile, another commented: “If someone had taught me math this way as a kid, I really believe I would have had a whole different life.”

Yet, some viewers noted that the method has its limits, especially with more complex figures, where you’d still need to be quite the maths guru to figure it out.

A sceptic remarked: “But what about 18% of 37? What the heck is 37% of 18? Still hard.”