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
Example 1: 11% of 550
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
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
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
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
Example 1: 11% of 550
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
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
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
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