The percent sign (%) has the mathematical value of one hundredth

. 30% represent 30 parts of 100 and can be expressed in decimal fraction form as 0.30 or in common fraction as

.
Percents are commonly use, but to use them in arithmetic application, one must convert them into decimal or common fraction. Conversions are crucial in solving a large variety of problems.
To convert a decimal as a percent, move the decimal point two places to the right and attach a percent sign (%).