In such cases, n zeros are put at the right end of N to get a new number M and then M is divided by 2n to find the required result of multiplication.
EXAMPLE; FIND THE VALUE OF 9482*25
SOL. HERE N= 9482, 5n =25=52
According to the rule ,
(N) (5N) (M)
HERE n=2 hence two zeros are put.M has been divided by 22 as n=2