**To determine a percentage, divide the actual number by the total possible number, and multiply the result by 100.** For example, if four out of five doctors agree on something, enter the equation in a calculator as "4 ÷ 5 x 100." The result, 80, is the percentage.

Percent literally means per hundred and is used to express what the numerator on a fraction would be if the denominator were equal to 100. By using the common denominator of 100, it becomes simpler to use fractions in calculations because the common number system is based on multiples of 10. This method of calculation allows for the simple movement of the decimal point rather than painstaking division.