A simple math life hack on how to quickly calculate a percentage of a number
A simple math life hack on how to quickly calculate a percentage of a number
Anonim

With this trick, the amount of the discount in the store can be found out in a couple of seconds.

A simple math life hack on how to quickly calculate a percentage of a number
A simple math life hack on how to quickly calculate a percentage of a number

It is not so easy to quickly calculate the percentage of a number without a calculator. Even if you are good at dividing and multiplying in your head, you are unlikely to quickly find, for example, 4% of 75. If you know one mathematical trick, then the answer can be obtained instantly.

Everything is extremely simple: x% of y = y% of x. In other words, 4% of 75 = 75% of 4. In this example, 75% of 4 is much easier to find - 3. If you check the first part, you get the same thing: 75/100 * 4 = 3.

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 recalled this simple rule on Twitter. And judging by 6,000 retweets and 17,000 likes, many users had no idea about such a trick. However, it should be noted that it is not always possible to use it. There are also "inconvenient" numbers where such a trick will not work. For example, 21% of 27 or 19% of 89.

Do you know such tricks, which are not known to everyone? Share in the comments.

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