Percents: Converting and Calculating

Understanding Percents and Converting with Decimals

A percent represents a ratio or fraction with a base denominator of 100. The percent symbol '%' denotes parts per hundred. Because percents express a share out of a hundred, one whole is equivalent to exactly 100 percent. When considering baseline boundaries, zero percent of any finite quantity is always equal to zero, while one hundred percent of any quantity is equal to the quantity itself.

To convert a percent to a decimal, divide the percent value by 100. In practical computation, this is done when you move the decimal point two places to the left and drop the percent symbol. For example, a percent of 75% converted to a decimal is 0.75. When handling a single-digit percent like 5%, moving the decimal point two places to the left yields 0.05. A percent greater than 100%, such as 250%, converts to a decimal greater than one, which is 2.5. Similarly, a fractional percent such as 0.4% converts to the decimal 0.004.

To convert a decimal to a percent, the reverse operation is performed: multiply the decimal by 100. In practice, move the decimal point two places to the right and append the percent symbol. For instance, the decimal 0.85 converts to 85%, and the decimal 0.03 converts to 3%. When working with values greater than one, the decimal 1.25 converts to 125%. For very small decimals, the decimal 0.006 converts to 0.6%.