Let us understand it by taking two examples.

Multiply 99 × 97

Multiply 103 × 105
Steps to perform this are:
 Find by how much the number is more or less than the power of 100 and write it on the right side of the vertical line.
 Either cross subtracts or cross add. This will form the first part of the final answer.
 Multiply the right side of the vertical line and this shall form the right side of the result.
03 15
 Add this multiplied number to the end giving 9603 and 10815 respectively.
This is how you can multiply numbers close to 100 in just 3 steps.
Try some on your own.
 102 x 105
 98 x 93
 99 x 99
thank you!