What Does Percentage Mean?

A percentage in mathematics represents a ratio or number that is a fraction of 100. Percentages provide a way to represent a relationship between two numbers in a simple form. Other common forms include ratios, fractions, and decimals. Percentages usually use the "%" symbol after the number, or can also be written as "percent" or "pct".

For example, 40% is equal to the decimal 0.40, meaning 40 out of 100. If a class has 30 students and 12 are girls, the ratio is 12 ÷ 30 = 0.4. Multiplying by 100 gives 0.4 × 100 = 40%. So, 12 out of 30 students being girls means 40% of the class.

Percentages are commonly used in exams, discounts, statistics, and real-life comparisons to make numbers easier to understand.

History

In Ancient Rome, long before the decimal system existed, fractions were often used based on 1/100. For example, Emperor Augustus imposed a tax of 1/100 on items sold at auction, called the Centesima Rerum Venalium. Similar to today's percentages, people were accustomed to utilizing 1/100 as a fraction of 1 in ancient Rome. During the Middle Ages, as the development of trade and monetary systems expanded, fractions on a scale of 1-H became increasingly prevalent. Math texts in the late 1400s and early 1500s began to introduce this method of calculating, especially regarding profit/loss, interest, and simple business calculations. With the evolution of interest and other financial values being expressed as a part of 100 in the 1600s, the percentage system gradually emerged as it finally exists today.