Friday, June 8, 2012

Multiplication of those numbers whose Difference is 10 and last digits are 5:

STEP 1: Square of the first digit of the greater number
STEP 2: Substract 1 from Square
STEP 3: Add 75 in last


Example:

25*35= Square of the first digit(3^2=9) of the greater number(35) - 1 = 8
and then 75.=. 875

35*45 = 4^2-1 = 16-1 =1575
15*25 = 2^2-1 = 3 =375
35*45 = 4^2-1 = 15 =1575
55*65 = 6^2-1 = 35 =3575


2 comments:

  1. 25*35= Square of the first digit(3^2=9) of the greater number(35) - 1 = 8
    and then 75.=. 875

    35*45 = 4^2-1 = 16-1 =1575
    15*25 = 2^2-1 = 3 =375
    35*45 = 4^2-1 = 15 =1575
    55*65 = 6^2-1 = 35 =3575
    same way for 3 digits
    Example:115*125 first 2 digits of greater number 12 multiply with same digits(12*12) =144 - 1 = 143 and then 75 = 14375

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