Divide 999 by 5 in 2 seconds

You can divide 999 by 5 in 2 seconds or less using this math trick.

999

Step 1

First you need to memorize 1.8. You get 1.8 when you divide 9 by 5.

Step 2

Leave some space between 1 and the decimal point: 1     .8

Step 3

Put 99 between 1 and the decimal point.

199.8

999 divided by 5 = 199.8

We can try another example with more 9s.

Divide 999999 by 5

999999 ÷ 5 = ?

Step 1

Write down 1.8

Step 2

Leave some space between 1 and the decimal point. This time you may have to leave more space since you have many 9s to put between 1 and the decimal point:

1               .8

Step 3

Put 99999 between 1 and .8

199999.8

999999 divided by 5 = 199999.8

Another trick to divide 999 by 5

The other trick that you can use to quickly perform the division is to rewrite 999 as   

1000 - 1 since 999 = 1000 - 1. Then divide (1000 - 1) by 5

(1000 - 1) ÷ 5 = (1000 ÷ 5) - (1 ÷ 5) = 200 - 0.2 = 199.8