Nikhilam Navatascaramam Dasatah

The formula simply means : “all from 9 and the last from 10”. The formula can be very effectively applied in multiplication of numbers, which are nearer to bases like 10, 100, 1000 i.e., to the powers of 10 . The procedure of multiplication using the Nikhilam involves minimum number of steps, space, saves time and you only need to do mental calculations. The numbers taken can be either less than or more than the base considered. The difference between the number and the base is termed as deviation. Deviation may be positive or negative. Positive deviation is written without the positive sign and the negative deviation, is written using Rekhank (a bar on the number).