Bank exam

2 digit multiplication trick whose tens digit is same

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2 digit multiplication trick whose tens digit is same
You must be wondering we have learnt so many multiplication tricks for 2 digit numbers,so how is this going to be helpful.Well, Knowing new tricks and where the trick can be applied to get the answer quickly can make all the difference. 2 digit multiplication trick whose tens digit is same is one of those tricks that you will learn today.

Condition to apply this trick is 
When the ten’s place digit is same and the unit’s place digits add up to 10 then you can apply a shortcut trick to easily multiply any 2 digit numbers.

2 digit multiplication trick whose tens digit is same

Now,let us see the steps in detail

Step 1:To get the unit’s place digit multiply the unit’s place digit of the both the numbers.

Step 2:To get the ten’s place digit multiply the ten’s place digit with its consecutive(next) number.

Step 3:Place the result obtained in step 2 to the left of the result obtained in step 1.

Let us now practice some examples

Example 1: 26 x 24=?
We observe that ten’s place digit of both numbers=2
and by adding unit’s place digit of both numbers(6+4=10)we get 10.

Hence, we can apply this trick

Step 1:Multiplying the unit’s place digits we get
Unit’s place digit=6 x 4=24

Step 2:Multiplying ten’s place digit by its consecutive number we get
Ten’s place digit=2 x 3=6

Step 3:Placing the result of step 2 to the left of the result obtained in step 1 we get
624

Ans  26 x 24=624

Example 2: 43 x 47=?
We observe that ten’s place digit of both numbers=4
and by adding unit’s place digit of both numbers(3+7=10)we get 10

Step 1:Multiplying the unit’s place digits we get
Unit’s place digit=3 x 7=21

Step 2: Multiplying ten’s place digit by its consecutive number we get
Ten’s place digit=4 x 5=20

Step 3:Placing the result of step 2 to the left of the result obtained in step 1 we get
2021

Ans  43 x 47=2021

Example 3: 38 x 32=?
We observe that ten’s place digit of both numbers=3
and by adding unit’s place digit of both numbers(8+2=10)we get 10

Step 1:Multiplying the unit’s place digits we get
Unit’s place digit=8 x 2=16

Step 2: Multiplying ten’s place digit by its consecutive number we get
Ten’s place digit=3 x 4=12

Step 3:Placing the result of step 2 to the left of the result obtained in step 1 we get
1216

Ans  38 x 32=1216

Example 4: 65 x 65=?
We observe that ten’s place digit of both numbers=6
and by adding unit’s place digit of both numbers(5+5=10)we get 10

Step 1:Multiplying the unit’s place digits we get
Unit’s place digit=5 x 5=25

Step 2: Multiplying ten’s place digit by its consecutive number we get
Ten’s place digit=6 x 7=42

Step 3:Placing the result of step 2 to the left of the result obtained in step 1 we get
4225

Ans  65 x 65=4225

Example 5: 71 x 79=?
We observe that ten’s place digit of both numbers=7
and by adding unit’s place digit of both numbers(1+9=10)we get 10

Step 1:Multiplying the unit’s place digits we get
Unit’s place digit=1 x 9=09

Step 2: Multiplying ten’s place digit by its consecutive number we get
Ten’s place digit=7 x 8=56

Step 3:Placing the result of step 2 to the left of the result obtained in step 1 we get
5609

Ans  71 x 79=5609

What is complement of a number

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What is complement of a number
What is complement of a number

The distance of a number from a convenient round number(base) or how far the number is from its base is known as the complement of a number.
Numbers such as 10,100,1000 are usually taken as bases as they are friendly numbers.
It is a simple concept but very helpful when you apply this concept to solve problems.
Suppose you want to substract two difficult numbers then if you know the complement of the numbers then you will be surprised to see how quickly you can mentally calculate the answer.

Let us now find out the complements of numbers taking different bases.

First lets start finding complement of numbers from 1 to 9 with 10 as base
10-1=9
9 is a complement of 1

10-2=8
8 is a complement of 2

10-3=7
7 is a complement of 3

10-4=6
6 is a complement of 4

10-5=5
5 is a complement of 5

10-6=4
4 is a complement of 6

10-7=3
3 is a complement of 7

10-8=2
2 is a complement of 8.

10-9=1
1 is a complement of 9.

Now lets take the base as 100 and find complements of numbers

To find the complement of a number with 100 as base follow the below steps
For the unit’s place digit find the complement of the units place digit with 10 as base
For the ten’s place digit find the complement of the ten’s place digit with 9 as base

We shall now practice few examples to perfect the skill that we learnt
100-11=?
Steps
For the unit’s place digit find the complement of 1 with base 10 (10-1=9)
For the ten’s place digit find the complement of 1 with base 9 (9-1=8)

Ans 100-11=89

100-21=?
Unit’splace digit=Complement of 1 with base 10 is 9(10-1=9)
Ten’s place digit=Complement of 2 with base 9 is 7(9-2=7)

Ans 100-21=79

100-42=?
Unit’splace digit=Complement of 2 with base 10 is 8 (10-2=8)
Ten’s place digit=Complement of 4 with base 9 is 5 (9-4=5)

Ans 100-42=58

Now lets take the base as 1000 and find complements of numbers

To find the complement of a number with 1000 as base follow the below steps
For the unit’s place digit find the complement of the units place digit with 10 as base
For the ten’s place digit find the complement of the ten’s place digit with 9 as base
For the hundreth’s place digit find the complement of the hundreth’s place digit with 9 as base

We shall now practice some examples
1000-121=?
Unit’splace digit=Complement of 1 with base 10 is 9 (10-1=9)
Ten’s place digit=Complement of 2 with base 9 is 7 (9-2=7)
Hundreth’s place digit=Complement of 1 with base 9 is 8 (9-1=8)

Ans 1000-121=879

1000-472=?

Unit’splace digit=Complement of 2 with base 10 is 8 (10-2=8)
Ten’s place digit=Complement of 7 with base 9 is 2 (9-7=2)
Hundreth’s place digit=Complement of 4 with base 9 is 5 (9-4=5)

Ans 1000-472=528

Note
If the unit’s place is 0 then Ignore the 0 and start finding the complement of the number from the next digit.
For example lets say we want to find the complement of 220
1000-220=?
Unit’s place digit=0
Ten’s place digit =Complement of 2 with base 10 is 8 (10-2=8)
Hundreth’s place digit=Complement of 2 with base 9 is 7 (9-2=7)

Ans 1000-220=780

1000-470=?
Unit’s place digit=0
Ten’s place digit =Complement of 7 with base 10 is 3 (10-7=3)
Hundreth’s place digit=Complement of 4 with base 9 is 5 (9-4=5)

Ans 1000-470=530

More Math tricks>>

3 digit multiplication trick in banking

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3 digit multiplication trick in banking
3 digit multiplication trick


A person who knows math tricks certainly has an edge over the others.With the ability to rapid do mental calculation one will not only be able to score higher marks in competitive exams but will also enhance his mental sharpness enormously. Its fun to calculate this way after all, steps of calculation need not be shown on paper!




Below we shall discuss one such multiplication trick wherein you will be able to multiply any two 3 digit numbers easily within seconds.
One thing to remember here is that both the numbers should be close to 100.The closer they are the easier it is to multiply.

Here are steps to do the 3 digit multiplication in detail

Step 1:Find the difference of each of the numbers from 100
Step 2:Multiply the differences that you found in step 1 to get the unit’s place digit
Step 3:Add the differences of both the numbers to 100 and place them to the left of the result obtained in step 2.

Let us now consider an example to understand better

Example 1: 102 x 103
Here we notice that both the numbers are close to 100
We shall apply the technique that we learnt 

Step 1:First we find the differences of the numbers
We observe that 
102 is 2 more than 100 so the difference is 2
103 is 3 more than 100 so the difference is 3

Step 2:Multiplying the differences 
we get,
2 x 3=6 which is the unit’s place digit.

Step 3:Now to find the rest of the number adding the differences to 100 
we get,
2+3+100=105

Placing 105 to the left of the result obtained in step 2(6)
we get 
102 x 103=10506

Ans 10506


Try multiplying the below numbers using the above trick and see how fast you are able to do it
(1)101 x 102
(2)102 x 104
(3)103 x 104
(4)104 x 105
(5)105 x 106
(6)106 x 107
(7)107 x 108
(8)108 x 109

Shortcut to square any number from 100 to 120

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Shortcut to square any number from 100-120
Shortcut to square any number from 100 to 120 using base method. Base method is popularly used to find square of numbers when the numbers are close to a base.By choosing the right base you will arrive at your answer quickly.
So whenever you see 102,101,112,106 it should strike to you immediately .


Hey! this is quite close to 100 so let me take the base as 100 and see if I can get the answer soon.

Here we discuss the shortcut method to square any number from 100 to 120 using the base method.

Lets go through the steps now

Examples

Example 1: Find square of 102 in seconds?

Step 1:Take 100 as base and see how far the number is from 100.
Add the given number and its deviation.
Lets say you need to square 102.
Here you can notice that the number is 2 more than 100.
Adding the given number(102) and its deviation(2)
we get,
102+2=104

Step 2:Square the deviation(2)and place it next to the result obtained in step 1.
Squaring we get,
22=4

Ans 10404

Example 2: Find square of 103 in seconds?

Step 1:Take 100 as base and see how far the number is from 100.
Add the given number and its deviation.

Here you can notice that the number is 3 more than 100.
Adding the given number(103) and its deviation(3)
we get,
103+3=106

Step 2:Square the deviation(3)and place it next to the result obtained in step 1.
Squaring we get,
32=9

Ans 10609

Example 3: Find square of 104 in seconds?

Step 1:Take 100 as base and see how far the number is from 100.
Add the given number and its deviation.

Here you can notice that the number is 4 more than 100.
Adding the given number(104) and its deviation(4)
we get,
104+4=108

Step 2:Square the deviation(3)and place it next to the result obtained in step 1.
Squaring we get,
42=16

Ans 10816

Decoding words trick for bank exams

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Decoding words trick for bank exams

Decoding words trick to your rescue to help you decode words quicker.These type of problems are often asked in Reasoning ability section of bank exams. Knowing the technique to decode letters will help in arriving at the answer within seconds.
There are different types of decoding.

Today we shall see problems of the following type 
In a certain code, a word is 
written as some word(code). How is another word written in that code?

Examples of Decoding words trick to solve reasoning problems


Let us see the steps to decode the letters of word 

Step 1:First of all write down all the alphabets from A to Z in the following manner
A=1,B=2,C=3,D=4,E=5,F=6,G=7,H=8,I=9,J=10,K=11,L=12,M=13,N=14,O=15,P=16,Q=17,R=18,S=19,T=20,U=21,V=22,W=23,X=24,Y=25,Z=26

Step 2:Now write the given word and the code in the form of numbers by substituting the value of the letters with their corresponding numbers.
Step 3:Compare the letter and the code and try to identify the pattern it is following.
       To identify the pattern check 2 things
       (a)Is there a change in the order of the letters or not
       (b)After substituting each of the letters with numbers see if the number increased or decreased and by how much. Step 4:Now write the another word that is to be written in that code in the form of numbers as you did in step 2.

Step 5:Apply the pattern that you identified in step 3 to the word to be decoded.

Step 6:Substitute the letters corresponding to the numbers of the pattern


Let us consider an example to understand better

Example 1:In a certain code, ‘TRICK’ is written as ‘SQHBJ’. How ‘LIGHT’ is written in that code?

Step 1:We write the Alphabetic series as
A=1,B=2,C=3,D=4,E=5,F=6,G=7,H=8,I=9,J=10,K=11,L=12,M=13,N=14,O=15,
P=16,Q=17,R=18,S=19,T=20,U=21,V=22,W=23,X=24,Y=25,Z=26

Step 2:Substituting the numbers in the word and the code
TRICK-20,18,9,3,11
SQHBJ-19,17,8,2,10

Step 3:Comparing the order of the letters of the word with the code, we notice that
there is no change in the order of the letters
Next we check if there is increase or decrease, we find that
Pattern here is 19=20-1,17=18-1,8=9-1,2=3-1,10=11-1
We have successfully identified the pattern as decreasing by 1. 

Step 4:Substituting the numbers in the word to be decoded
LIGHT-12,9,7,8,20

Step 5:Applying the pattern we identified in step 3 to the word LIGHT we get
         12-1=11,9-1=8,7-1=6,8-1=7,20-1=19
         we get,
         11,8,6,7,19

Step 6:Substitute the letters corresponding to numbers of the pattern


Ans Decoded word of LIGHT will be KHFGS