An Easy Method for Multiplication By 5

Here’s a neat trick for multiplying numbers by 5.

First take your number: I’ll chose 36 for this example. Now usually we wouldn’t know what 36*5 is off the top of our heads. This trick makes it easy.

Step 1: Visualize 36/2 in your head. It’s easier than trying to multiply by 5, right? 36/12 = 18.0, as it is quite easy to see. The .0 on the end seems unnecessary, but becomes important.

Step 2: Remove the decimal point. 18.0 -> 180

Step 3: Check. 36*5 = 180. And there you have it, 36*5 computed in your head in a matter of seconds.

But let’s try this with an odd number…25, perhaps?

Step 1: 25/2 = 12.5

Step 2: 12.5 -> 125

Step 3: 25*5 = 125.

Easy peasy.

You can even do this for 3 digit numbers, too!

Example: 222*5
222/2 = 111.0 -> 1110

Example: 465*5
465/2 = 232.5 -> 2325

Try it!

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