Rounding a number results in a less accurate, but simpler and easier-to-use figure. Rounding to two decimal places, also known as rounding to the nearest hundredth, is useful because the method can express an unrounded number in terms of currency.
The U.S. currency system, among others, uses denominations in the hundredths, known as cents. Rounding to two decimal places results in rounding to the nearest cent. The hundredths rounding method is especially useful when dealing with multiplication or division of a currency value, as the resulting value is often not expressed to clean hundredths. Rounding also cuts down on work time when using the rounded number for subsequent calculations.