In Such a cases, n zero are put at the right end of N to make a new number M and then N is added to this new number to get the result. Clearly, M+N is the result of multiplication.
Example- Multiply 4241 with 101
Solution. Here, N=4241, (10n +1)=(102 +1)= 101
According to the rule,
(N) (M) (N)
Therefore- (M+N) = 424100 + 4241 = 428341