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Home-> Vedic / Quicker Math-> Multiplication by two-digit Number

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


So answer is 156.

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)


So answer is 306.

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)

So answer is 8004.


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
ANSWERS :
(1) 2451 (2) 2142 (3) 1634 (4) 5152 (5) 1539 (6) 2277 (7) 2001 (8) 4402 (9) 629 (10) 8633



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