CLASS-8
IMPORTANT RULES OF PERCENTAGE

IMPORTANT RULES OF PERCENTAGE 

The percentage is one of the very important forms of solving a problem for the purpose of a step forward to advanced mathematics. Percentage is required for any kind of mathematics including research-oriented projects or for any kind of higher grade mathematical project. Percent or per centum or per century means “ in a hundred “, thus when we say 26 percent, we mean 26 out of 100. Symbolically this can be written as 26%.


Some Conversion Rules Of Percentage –

Rule.1 ) To convert a percentage into a fraction, we will write the number as the numerator and 100 as the denominator and then reduce this fraction to its simplest form. we can also express the fraction as a ratio.


Rule.2 ) To convert a fraction into a percentage, multiply the fraction by 100 and add the % symbol, since ratios are essentially fractions, you can also express a ratio as a percentage.


Rule.3) To convert a percentage into a decimal, we have to remove the % sign and shift the decimal point in the number by two places to the left.


Rule.4) To convert decimal into a percentage, shift the decimal point in the number by two places to the right, and add the % sign.


Rule.5) To find a given percentage of a quantity, write the percentage as a fraction and multiply the quantity by the fraction.                                                            x

              x % of y = --------- X  y

                              100

Rule. 6)  To express a given quantity as a percentage of another quantity, to express a given quantity as a percentage of another quantity of the same kind, now we would like to divide the given quantity by the other quantity, multiply the result by 100 and add the % sign.

                                   A

   A as percentage of B = ( ------- X 100 ) % of B

                                   B

Rule.7) To find a quantity from a given percentage of a quantity, to find a quantity from a given percentage of a quantity, express the given percentage as a fraction and divide the given quantity by this fraction.


Rule.8) To find the percentage change in a quantity, to find the percentage change in a quantity, write the change in the quantity as the numerator and the original quantity as the denominator, and then multiply the fraction by 100.


                            Change In The Quantity

 Percentage Change = ------------------------ X 100

                               Original Quantity