Multiply any number by 9 or 99 or 999 or 9999 etc

The magic of 9

Can you multiply 65678*99999 in 5 seconds or less.

Sounds impossible isn't it.

Well the word impossible itself says I am possible. Let's see how can we do it

Step 1: Write the number 65678 and subtract 1 from it. You get the left-hand side of the answer that is 65677.

Step 2: Now subtract each digit of the answer from 9. You get the number 34322.

This is the right-hand side of the answer.

So 65678*99999 is 6567734322.

Simple isn't it.

Now let's do some simple ones

63 * 99

Step 1: 63-1 = 62 i.e. left-hand side of the answer.

Step 2: subtract 6 from 9 and 2 from 9.

You get 37 i.e. right-hand side of the answer

So 63*99 = 6237.

Super easy isn't it