aditi
Member • Aug 9, 2006
multiplication by all 9's
Multiplication by all 9's wherein multiplicant being of equal no. of digits as of multiplier. Solved eg below.
2148 * 9999 = 21477852 - This is solved just in fraction of seconds... How????
Reduce the number 2148 by 1 (2147) which is left part of answer. For next 4 digits write the complementary numbers from 9 in the same order of 2147 i.e 7852 ( i.e 9-2, 9-1, 9-4 & 9-7)
:smile:
2148 * 9999 = 21477852 - This is solved just in fraction of seconds... How????
Reduce the number 2148 by 1 (2147) which is left part of answer. For next 4 digits write the complementary numbers from 9 in the same order of 2147 i.e 7852 ( i.e 9-2, 9-1, 9-4 & 9-7)
:smile: