Percentage, often represented by "%," is a way to say parts per 100. Percentages can be calculated by dividing any fractions that result in a decimal quotient and then multiplying by 100. This can be done by hand or estimated mentally in under a minute in many cases. Use of a calculator is optional.
Determine the whole and the parts
The end result of calculated percentages lets 100 be the whole. Some part-whole relationships begin with a 100-part whole. For example, if you have a quarter and a nickel, you have 30 cents, or 30 parts of a whole that equals 100. However, many wholes are not made of 100 parts. For example, you might have 11 ounces out of the 16-ounce pound, or you could have worked 20 hours of your 32-hour work week.
Divide the parts by the whole
Divide the parts present by the number of parts required to make up the whole. These expressions look like fractions. For example, write 30 cents as 30/100 or 11 ounces as 11/16. Take the quotient, usually in the form of a decimal. 30/100 = 0.30 11/16 = 0.6875
Multiply by 100
Multiply the decimal by 100. The product is the percentage or parts per hundred. 0.30 * 100 = 30% 0.6875 * 100 = 68.75% meaning that if the whole were 100 ounces, you would have almost 69 at the present rate.