Overview of unit conversion steps Identify the equality relationship between the quantities that are being converted (e.g. 1mile=5280foot ). Metric prefixes (see the table below) are just a shorthand for an equality relationship between units, and are based on powers of 10 (e.g. 1millimeter=103meter ) Use the equality relationship to obtain a conversion factor that is a ratio of the units. Since the numerator and denominator of a conversion factor are equal, it will always have a value of exactly 1. Therefore, when you multiply a quantity by a conversion factor, it will not change its inherent value, rather just the associated units. The conversion factor can have either of the units in the numerator, with the other in the denominator. The placement of the units depends on the quantity being converted. (e.g. 5280foot1mile or 1mile5280foot ) Multiply the quantity to be converted by the appropriate factor obtained in the step above. If the same unit appears in the numerator and denominator of a fraction, it cancels. Therefore, write your conversion factor such that the unit being converted cancels out. Be sure to write these conversion expressions with both the numerical quantities and the units so that they can be correctly evaluated (e.g. 14,411foot1mile5280foot=2.7294mile ) To convert quantities with compound units, apply multiple factors using the steps above. To check that the units being converted have all cancelled out and only the desired units remain, you