Man's clever maths trick to calculate percentage blows up the internet

A copywriter living in the UK has shared a "fascinating little life hack" that you'll wish you'd always known. Photo / Getty Images

Twitter isn't always the best place to learn new things.

Sure, you could learn about the worst red carpet looks from the Oscars, or watch a public celebrity feud unfold in real time, but Twitter isn't the ideal platform for scholarly pursuits.

Until now.

Ben Stephens, a copywriter living in the UK, shared a simple trick to calculate percentages on Twitter last week.

Describing it as a "fascinating little life hack", Ben showed his followers that simply flipping your numbers, then multiplying them together, will calculate the percentage of any number you desire.

For example, 8 per cent of 25 is much easier to calculate, if you flip the numbers around, and multiply 25 by 8.

Divide that by 100, and you've got 2.

So 8 per cent of 25 = 2. Voila!

Fascinating little life hack, for doing percentages:

x% of y = y% of x

So, for example, if you needed to work out 4% of 75 in your head, just flip it and and do 75% of 4, which is easier.

— Ben Stephens (@stephens_ben) March 3, 2019

The response to Ben's hack has grown to epic proportions in the last four days, with the post attracting more than 11,000 likes and almost 4,000 retweets.

People's comments circulated around how rocked they were by the simple magic of Ben's trick.

One person claimed: "every teacher I have ever had has failed me".

Others who work around numbers every day couldn't quite believe they had never been shown the simple 'switcheroo'.

This is the day Twitter changed my life.

I earn a living as a scientist, juggling numbers every day, and I have never realised this:

X percent of Y is equal to Y percent of X

7% of 50 = 50% of 7 = 3.5

Not sure whether I should be happy or embarrassed... Maybe both. https://t.co/0rpVaJgPUh

— Antoine van Oijen 🔬🧫🧬 (@van__Oijen) March 5, 2019

As someone who Quite Likes Maths I cannot believe I hadn’t realised this until the age of 47. https://t.co/4MFf8DuB6s

— Rhodri Marsden (@rhodri) March 6, 2019

More maths sorcery! @SLSingh https://t.co/csU7BbK9PA

— Prof Alice Roberts (@theAliceRoberts) March 5, 2019

For Ben, who claimed to have spent years talking about the perils of Brexit and Donald Trump, the instant success of his mathematical trick was rather amusing.

Typical. I spend years on here banging on about Trump & Brexit and making all kinds of smart points & trying to get people to listen to my dumb song videos, then I pop out one tweet about maths (a subject about which I have never tweeted before) and it sets the internet on fire. pic.twitter.com/1l0djQWhXe

— Ben Stephens (@stephens_ben) March 5, 2019

Keep up the good work, Ben. Can't wait to see what you've got for us next.