Percentages are used in almost every aspect of life. In fact, you probably use them every day, for things such as tax, or discounts. The first time percentages were used to calculate tax was back in Ancient Rome. The first Roman emperor, Augustus, issued a tax on goods sold. The tax was 1/100, or one hundred times less than the value of the sold goods. Today, however, we wouldn’t say 1/100, or 17/100, we would simply say 1% or 17%.