“(Q) Multiply 456789 by 999999 We subtract 1 from 456789 and get the answer 456788. We write this down on the left hand side. Next, we subtract each of the digits of 456788 (left hand side) from 9 and get 543211 which becomes the right hand part of our answer. The complete answer is 456788543211   More examples: The simplicity of this method can be vouched from the examples given above. Now we move to Case 2. In this case, we will multiply a given number with a higher number of nines.”