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

Vedic math trick to check multiplication

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Vedic math trick to check multiplication

Vedic maths is the ancient mathmematics discovered from the vedas by Sri Bharati Krsna Tirthaji. My Salutations to the Swamiji for providing us with such a useful and magical tool to solve complex mathematical problems. Vedic math trick to check multiplication is one such amazing trick. This Vedic math trick is an easy method to check if the multiplication of any two given numbers is done correctly.

Vedic math trick to check multiplication steps

Let us now see the how it is done in the steps below.

Step 1:Find the sum of the digits of the numbers to be multiplied separately.

Step 2:Find the sum of the digits of the answer you got on multiplying each of the numbers.

Step 3:Multiply the results obtained in step 1 and find its sum of digits.

Step 4:Compare the sum of digits obtained in step 2 with the sum of the digits obtained in step 3.
If both are same then it means you have multiplied correctly.

Examples
Let us consider an example to understand better

Example 1: 105 x 140=14700
We want to check whether 14700 is the correct answer.
Here is how we can check it
Step 1:Finding sum of the digits of 105
         105=1+0+5=6
         Finding sum of digits of 140
         140=1+4+0=5
Step 2:Finding sum of digits of the answer 14700
          14700=1+4+7+0+0=12=1+2=3

Step 3:Multiplying the results obtained in step 1 we get,
          6 x 5=30
        finding sum of digits of 30
        30=3+0=3

Step 4:Comparing result obtained in step 2 with result obtained in step 3 we notice that
Sum of digits in the both the cases is 3.

Hence, we can conclude that our multiplication is right and we arrived at the correct answer.



Shortcut to divide 2 digit number by 5

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Shortcut to divide any 2 digit number by 5

Shortcut to divide 2 digit by 5 is an amazing trick you can use to get answer in seconds. Speed with accuracy makes the difference between success and failure in competitive exams.

Shortcut to divide 2 digit by 5 steps

Let us see the steps on how to divide any number by 5

Step 1: Double the given number.

Step 2: Shift the decimal point to the left by one place.

Now we shall practice some examples using this trick

Examples

Example 1: 42/5=?
Step 1:By doubling 42 we get 84.

Step 2:By shifting the decimal point to the left by one place we get 8.4

Ans  42/5=8.4

Example 2:18/5=?
Step 1: By doubling 18 we get 36.

Step 2: By shifting the decimal point to the left by one place we get 3.6

Ans  18/5=3.6

Example 3:24/5=?
Step 1: By doubling 24 we get 48.

Step 2: By shifting the decimal point to the left by one place we get 4.8

Ans  24/5=4.8

Example 4: 73/5=?
Step 1: By doubling 73 we get 146.

Step 2: By shifting the decimal point to the left by one place we get 14.6

Ans  73/5=14.6

Example 5: 37/5=?
Step 1: By doubling 37 we get 74.

Step 2: By shifting the decimal point to the left by one place we get 7.4

Ans  37/5=7.4

Shortcut to find percentage of a number within seconds

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Shortcut to find percentage of a number within seconds

Shortcut to find percentage of a number is one of the coolest trick which makes maths fun. With this trick you can mentally find the percentage of any number within seconds. 

Let us understand a simple concept on percentages here

100% of a number will be the number itself
ex:100% of 360 will be 360

50% of a number will be half of the number
ex:50% of 360 will be 360/2=180

25% of a number will be quarter of the number or half of 50% of the number
ex:25% of 360 will be 360/4 or 180/2=90

10% of a number can be found by shifting the decimal point by 1 place to the left.
ex:10% of 360 will be 36.0

5% of the number is half of 10% of a number
ex:5% of 360 will be 36/2=18

15% of the number will be the sum of 10% and 5% of a number
ex:15% of 360 will be (10% of 360)36+(5% of 360)18=54

1% of a number can be found by moving the decimal point by 2 places to the left.
ex:1% of 360 will be 3.60

Now that we know the concept let us see how we can apply this trick in the below examples

Examples to apply shortcut to find percentage of a number

Example 1: 11% of 550 is?
Step 1: Split the number into 2 numbers that we can easily find the percentage of. 
We can split 11% into 10% and 1%

Step 2: First we find 10% of 550 by shifting the decimal point to the left by 1 place.
We get,
10% of 550=55.0

Step 3: Now we need to find 1% of 550 by shifting the decimal point to the left by 2 places.
We get,
1% of 550=5.50

Step 4:Adding both the results
we get 10%+1%=55.0+5.50=60.50

Ans  11% of 550=60.50

Example 2:21% of 250 is?

Step 1: 21% can be split into 10%+10%+1%

Step 2: First we find 10% of 250 by shifting the decimal point to the left by one place
we get,
10% of 250=25.0

Step 3: Another 10% of 250 we get
10% of 250=25.0

Step 4:Now we need to find 1% of 250 by shifting the decimal point to the left by 2 places.
We get,
1% of 250=2.50

Step 5:Adding all the results we get,
10%+10%+1%=25+25+2.50=52.50

Ans  21% of 250=52.50

Example 3: 61% of 754 is?
Step 1:61% can be split into 50%+10%+1%

Step 2: First we find 50% of 754 which is half of the number
we get, 50% of 250=377

Step 3: First we find 10% of 754 by shifting the decimal point to the left by one place
we get, 10% of 754=75.4

Step 4:Now we need to find 1% of 754 by shifting the decimal point to the left by 2 places.
We get, 1% of 754=7.54

Step 5:Adding all the results we get,
  50%+10%+1%= 377+75.4+7.54=459.94

Ans   61% of 754=459.94

Example 4: 98% of 850 is?
Step 1: 98% can be split into 100% – 2%

Step 2: We know that 100% of 850 which is 850.

Step 3: Now we find 1% of 850 by shifting the decimal point to the left by 2 places
we get, 1% of 850= 8.5

Step 4:Now we find 2% of a number,

1% of 850 + 1% of 850=8.5 + 8.5

we get, 2% of 850= 17

Step 5:a Subtracting the results we get,
  100%- 2%= 850-17=833

Ans   98% of 850=833

Example 5: 95% of 620 is?

Step 1: 95% can be split into 100% – 5%

Step 2: We know that 100% of 620 which is 620.

Step 3: Now we find 10% of 620 by shifting the decimal point to the left by 1 place
we get, 10% of 620= 62

Step 4:Now we find 5% of 620 which is half of 10%

62/2= 31

we get, 5% of 62= 31

Step 5:a Subtracting the results we get,
  100%- 5%= 620-31=589

Ans   95% of 620=589