Multiply a Number by 5, 25 and 125

This is a simple trick to calculate any number by 5, 25 or 125.

5 = 10/2. If we are trying to multiply a number by 5, we can convert 5 to 10/2. For example,

56 x 5
= 56 x 10/2
= 56/2 x 10 = 280