Finding a percentage of a whole number



In this lesson, we learn how to find the percentage of a whole number.

Finding percentage of a whole number is basically a multiplication problem.

It is a product of the percentage and the whole number. The percentage is written as a decimal and multiplied with the whole number to give the percentage of the whole number.

Rules to find the percentage of a whole number

  • The percentage of a whole number is written as a product of the percentage and the whole number. For example: 60% of 98 is written as 60% × 98

  • The percentage then is written as a decimal. To do this, the decimal point is shifted two places to the left and the percent sign is dropped

    For example: 60% × 98 = 60.0% × 98 = 0.60 × 98

  • The multiplication of the decimal and the whole number is carried out and product finally gives the percentage of the whole number

    For example: 0.60 × 98 = 58.80

Formula

x% of y where x is any number and y is a whole number

x% of y = x% × y = 0.0x × y

What is 15% of 90?

Solution

Step 1:

15% of 90 = 15% × 90 = 15.0% × 90

Step 2:

To convert the percentage to a decimal, the decimal is shifted two places to left.

15.0% × 90 = 0.15 × 90

Step 3:

0.15 × 90 = 13.50

So, 15% of 90 = 13.50

What is 25% of 72?

Solution

Step 1:

25% of 72 = 25% × 72 = 25.0% × 72

Step 2:

To convert the percentage to a decimal, the decimal is shifted two places to left.

25.0% × 72 = 0.25 × 72

Step 3:

0.25 × 72 = 18.00

So, 25% of 72 = 18.00 = 18

What is 150% of 21?

Solution

Step 1:

150% of 21 = 150% × 21 = 150.0% × 21

Step 2:

To convert the percentage to a decimal, the decimal is shifted two places to left.

150.0% × 21 = 1.50 × 21

Step 3:

1.50 × 21 = 31.50

So, 150% of 21 = 31.50



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