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Published on March 31st, 2013 In category Division and Multiplication tricks | Maths

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Shortcut to multiply by 111, 101 and 1001

this article we will learn to multiply any numbers ( even with digits as large as , 7, 8 , or 12)

Trick to Multiply by 111

Suppose we have a number 748634 to be multiplied by 111. The rule is as follows

  1. The first digit of the number will be same i.e. 7
  2. The second digit will be 7 + 4 = 11 Since it is a 2 digit number 1 will carried to preceding number 1. So first digit will be 8 and second digit will 1 upto this stage
  3. The third digit will be 7 + 8 + 4 = 19 , keep 9 and take 1 to preceding digit so we have first 3 digits as 829
  4. The fourth digit will be (pl note this step) 4 + 8 + 6 (2nd + 3rd + 4rth) = 18, so now the first 4 digit will be 8308 as the 1 is carried forward and added to the 9 that become 1o and again 1 is carried forward
  5. The fifth digit will be 8 + 6 + 3 = 17 , 1 will be carried over and 5 digit will 83097
  6. The sixth digit will be 6 + 3 + 4 = 13, 1 will be carried forward and sixth digit will become 830983
  7. The seventh digit will be 3 + 4 = 7
  8. The eigth digit will be 4 itself so the answer will 83098374 You can check this will calulator itself, the solution looks tricky but it is quite simple

Summary of Trick: Keep the first digit and last digit same, keep adding the numbers in group of 3 except the ten digit number. Don’t forget to carry forward the numbers and add to the preceding numbers when it is more than 9 thats all. It will need a little bit of practice

Trick to Multiply by 101

Suppose we have same number 748634 to be multiplied by 101. The rule is as follows

  1. The first 2 digits in the answer is same 74
  2. The last 2 digit in the answer is same 34
  3. For the 3rd digit onward add the numbers to alternate numbers 7-4-8-6-3-4 , so add 7 + 8 = 15, 4 + 6 = 10, 8 + 3 = 11, 6 + 4 = 10
  4. For the third digit 7 +8 = 15, keep 5 and carry forward 1 so first 2 digit becomes 75 and 3 digits are 755
  5. For fourth digit use 4 +6= 10, keep 0 and carry forward 1 so 4 digit now becomes 7560
  6. For fifth digit take 8 +3 = 11, keep 1 and carry forward 1 then answer becomes 75611
  7. For sixth digit take 6 +4 =10 and carry forward 1 then answers becomes 756120

Just add last 2 digit to complete the answer 75612034

Trick to Multiply by 1001

Suppose we have same number 748634 to be multiplied by 1001. The rule is as follows

  1. The first 3 digit in answer is same i.e. 748
  2. For the fourth digit we need to add first digit to fourth one like 7 + 6 = 13 , then 4 + 3 = 7, then 8+4 = 12
  3. If you will note 0, 3, 4 are last digits and can’s be added in this way so we keep it as it is 034
  4. To form the answer fill in between last digits ( 634) and first digits (748)  by     1382,  1 will be carried forward to be added to 748 will become 749 and let over number is 382
  5. So answer is 749, 382, 634
 Some Other Good Post on tricks to multiply you can like are
1. Easy Multiplication Tricks  using vedic maths