Skip to main content

Multiplication Trick 6



1. Condition :  This trick is used when we multiply quickly two numbers near  a  multiple of a power of 10.
Example.  211×209, 189×191

Illustration 1 :     207×211

Numbers       Working Base       Difference    
 207                    2×100                 +7 
 211                    2×100                 +11 
 Solution: 
1st part / 2nd part(2 digits)
                   
[Number of digits in the 2nd part = Number of 0s in the base]
                          
2×(207+11) / 7×11(2 digits)
      2×218     /    77
         436       /    77
 Answer is   43677

Note: 1st part can either be 207+11 or 211+7 

Illustration 2 :     191×187

Numbers       Working Base       Difference    
 191                    2×100                 -9 
 187                    2×100                 -13 
 Solution: 
1st part / 2nd part(2 digits)
                   
[Number of digits in the 2nd part = Number of 0s in the base]
                          
2×(191-13)    /  9×13(2 digits)
    2×178         /    117
       356          /   117
 356+1(carry)/     17
       357          /    17
 Answer is  35717


Note: 1st part can either be 191-13 or 187-9

Illustration 3 :     2018×2012

Numbers       Working Base       Difference    
 2018                    2×1000                 +18 
 2012                    2×1000                 +12 
 Solution: 
1st part / 2nd part(2 digits)
                 
[Number of digits in the 2nd part = Number of 0s in the base]
                          
2×(2018+12) / 18×12(3 digits)
      2×2030     /     216
         4060       /     216
 Answer is   4060216

Note: 1st part can either be 2018+12 or 2012+18 
Try Now :
1.  205×209
2.  302×303
3.  2014×2016
4.  2025×2050
5.  40063×40003

  

Comments

Post a Comment

Popular posts from this blog

Rules of divisibility part -1

Rules of divisibility In Vedic mathematics, it can be determined whether any part of any other number can be given completely without dividing it by several methods. These methods are based on the law of divisibility. By using these rules, calculations related to factors, parts etc. are simplified. Law of divisibility by number 2 :- If unit digit of given number is divisible by 2 then the given number is divisible by 2 also.                                                                 or  If unit digit of given number is 0,2,4,6 or 8 , then given number is divisible by 2. Example :- 10 ,32 ,74 ,108 ,2058 etc. Law of divisibility by number 3 :- If the sum of digits of given number is divisible by 3, then the number is divisible by 3 also. Illustration 1:-  In 546532 sum of digits=5+4+6+5+3+2=25 25 is not divisible by 3, Hence the number 546532 is not divisible by 3. Illustration 2:-  In  287286 sum of digits=2+8+7+2+8+6=33 33 is divisible by 3, Hence the number 287286 is divisibl
2 comments
Read more

Octal and Hexadecimal Number

Complement of a Number    Types of Number system    Convert Decimal to Binary If you are new to this article, I strongly recommend to read our previous article before preceding this. In our previous article, we had already seen that binary number has a base of 2. It means that binary number contains 2 1 = 2 combinations which are 0 and 1. Similarly, Octal and Hexadecimal number has a fixed number of combinations. As we earlier know that octal has a base 8, then it contains 8 digits through 0 to 7 which means 2 3 =8 combinations and Hexadecimal has a base 16 which means it has 2 4 =16 combinations.                 If you are focusing on a sequence i.e. octal, hexadecimal. They are the combinations of increasing power of 2. Octal – 2 3 , Hexadecimal - 2 4 This power indicates how many bits are in a number for a particular number system Octal has 3 bits Hexadecimal has 4 bits This can be clear understand by following diagram-   Explain – In this diagram, first we co
Post a Comment
Read more

Hunters of the Animal World

    In the cycle of life, predators always occupy an important position. They are killers. But they kill, only to 'kill' their hunger. In fact, the story of the animal kingdom is full of predators trying to catch prey, and the prey trying to outwit predators. It is the balance between the two that takes the drama of life forward. In the wild, there is no place for the weak, whether it's the predator or the prey, and only the fittest survives. The hunters keep populations healthy by weeding out the old and the sick. Of course, there are also creatures that steal the prey caught by others, like hyenas.      We have collected information about some animals for which you must know. 1 . Bengal Tigers : The Bengal Tiger is found in the rainforests and grasslands of Bangladesh, Bhutan Burma, China, India and Nepal. Bengal tigers are extremely large, and the males are up to 3 meters in length. The Bengal tiger's fur is orange brown, with black stripes. It hunts deer, pigs, a
1 comment
Read more