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 Vedic Math / Quicker Math / Math Tricks :-

MULTIPLICATION BY TWO DIGIT-NUMBERS :

Ex. 1 : Solve => (1) 12x13 =? (2) 17x18 =? (3) 87x92 =?

Soln : (1) 12 x 13 = ?
Step I. Multiply the right-hand digits of multiplicand and multiplier (unit-digit of multiplicand with unit-digit of the multplier).
 1   2 1   3 6
as (2x3) = 6

Step II. Now, do cross-multiplication, ie, multiply 3 by 1 and 1 by-2. Add the two products and write down to the left of 6.
 1   2 1   3 56
as (3x1+2x1) = 5

Step III. In the last step we multiply the left-hand figures of both multiplicand and multiplier.
 1   2 1   3 156
as (1 X 1) = 1

Soln : (2) 17 x 18 = ?
Step I.
 1   7 1   8 6
(7 x 8 = 56, write down 6 and carry over 5)

Step II.
 1   7 1   8 0 6
(1x8+7x1+5 = 20, write down 0 and carry over 2)

Step III.
 1   7 1   8 3 0 6
(1x1+2 = 3, write it down)

Soln : (3) 87 x 92 = ?
Step I.
 8   7 9   2 4
(7x2 = 14, write down 4 and carry over 1)

Step II.
 8   7 9   2 0 4
(8x2+9x7+1 = 80, write down 0 and carry over 8)

Step III.
 8   7 9   2 8004
(8x9+8 =80)

Practice Question Solve the following:
(1) 57 x 43 (2) 51 x 42 (3) 38 x 43 (4) 56 x 92 (5) 81 x 19 (6) 23 x 99 (7) 29 x 69 (8) 62 x 71 (9) 17 x 37 (10) 97 x 89