 Hello and welcome to the session. In this session we discuss the following question which says find the sum by short method 657 plus 9. Let's see the solution now. We need to find the sum of 657 and 9 by short method that is we need to find 657 plus 9. Now we can write this as 657 plus, now we can write 9 as 10 minus 1. So this is equal to 657 plus 10 minus 1. Now 657 plus 10 is 667 minus 1 which is equal to 666. So we have got the sum 657 plus 9 is equal to 666. So this is our final answer. This completes the session. Hope you have understood the solution of this question.