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When neither the multiplicand nor the multiplier is sufficiently close to a convenient power of 10 than we can take a multiple of power of 10 and call it as the working base and then perform the necessary operation with its assistance. Example 1: 52 x 53 Step 1: Select the base as 50 = 10 x 5. We will call 5 as our multiplying factor (MF).

     275/6 = 2756   Answer

Step 2:  Proceeding as per Chapter 3 (Nikhilam) we obtain the RHS as 2 x 3 = 6 and LHS as (52 + 3) or (53 +2) = 55

Step 3:  Now we have to multiply the LHS by the MF so 55 x 5 = 275 (This is a very important and critical step)

Step 4:  Now combine the LHS and RHS to obtain the final answer as 2756

Note:  In this method the carry over from RHS, if required, must be performed as the last step after multiplying the LHS by MF.

 

Example 2:  53 x 54

LHS = (53 + 4) or (54 + 3) = 57

RHS = 3 x 4 = 12

Multiply LHS by MF: 57 x 5 = 285

Carry over 1 from the right side and add to LHS (285 + 1 = 286) and obtain the final answer as 2862

Note:  The rule of carry over states that the number of digits on the RHS is equal to the number of zeros in the base, is also applicable here.

 

Example 3:  67 x 68

B = 70 = 10 x 7

Take the base as 70 = 10 x 7 (Since both the numbers are closer to 70)

LHS = (67–2) or (68–3) =65

RHS = (-3) x (-2) = 6

 

Multiply LHS by MF: 65 x 7 = 455

Combine with RHS giving the final answer as 4556

 

Example 4:  203 x 204

B = 200 = 100 x 2

Take the base as 200 = 100 x 2

LHS:  (203 + 4) or (204 + 3) = 207

RHS: 3 x 4 = 12

Multiple LHS by MF:  207 x 2 = 414

Combine with RHS to get the final answer as 41412

 

Example 5: 3003 x 3006

B = 3000 = 1000 x 3

Take the base as 3000 = 1000 x 3

LHS (3003 + 6) or (3006 + 3) = 3009

RHS:  3 x 6 = 018 ( Note the base has three zeros so we need to add a preceding zero to make up 3 digits)

Multiply LHS by MF:  3009 x 3 = 9027

Combine LHS and RHS to derive the final answer as 9027018

 

Example 6:  52 x 48

B = 50 = 10 x 5

Taking the base as 50 = 10 x 5

LHS:(50 – 2) or (48 + 2) = 50

RHS = (+2) (-2) = -4

Multiply the LHS by MF: 50 x 5 = 250

Now increase one zero in LHS (As the base 50 has one zero) and then subtract the RHS from LHS to obtain the final answer.   2500 – 4 = 2496

 

Exercises: 

21 x 23 = 483

59 x 59 = 3481

46 x 44 = 2024

62 x 58 = 3596

7.7 x 7.8 = 60.06 (Remember to convert to whole numbers before performing any calculations)

82 x 83 = 6806

505 x 506 = 255530

9009 x 9009 = 81162081

192 x 193 = 37056

202 x 198 = 39996

 

 

 

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