Percent Operations

To find the percent of a number, write the percent as a fraction with 100 as the denominator and then multiply the fraction with the number

E.g. To find 5% of 20,
Write 5% as a fraction with 100 as denominator.
5% = 5
       100 

Then, multiply 5/100 with 20

Or, 5 x 20
    100

To solve questions such as 5 is 25% of what number:

Let the number be n

So, 5 is 25% of n

Or, 25 x n = 5
     100

Find n.

To make calculations easier round off the decimal costs to the nearest whole number

If the digit to the right of the digit to be rounded is 5 or greater, we will add 1 to the digit to be rounded. If digit is 4 or less, the digit to be rounded remains the same

Cost of a product after discount = Regular price of the product - Discount on the product

Cost of a product after sales tax = Regular price of the product + Sales tax on the product