Modern, more accurate measurement has corrected this problem today, but it has had some interesting effects on the customary system. For instance, the avoirdupois pound weighs sixteen ounces, while the apothecary pound weighs just twelve ounces. Also, many units measure the same quantity, such as the tun, hogshead, barrel, gallon, quart, pint, gill, fluid ounce, fluid dram, and US minim, which all measure liquid capacity in the customary system (Cardarelli 36-37). This notwithstanding, the largest detriment to the customary system is the awkward conversion factors associated with such seemingly arbitrary units. Conversions between units involve factors ranging from an easy two, between yards and fathoms, to a nightmarish thirty-one and a half, between gallons and barrels (Cardarelli 33,36). Since unwieldy conversion factors often produce repeating decimals, fractions must be used for mathematical conversions. As anyone with even basic experience in multiplying and dividing fractions knows, after a few operations, the fractions become excessively complex.
The metric system of measurement, on the other hand, has several advantages to complement these detriments of the customary system. Most importantly, the metric system has only one unit for each measured quantity. For example, the meter is the only unit for measuring distance, and the gram is likewise the only unit for measuring mass ("Go Metric" in link "Commonly"). This system eliminates the need for the bulky conversion factors between units. The metric system's units are also arranged with different prefixes in multiples of ten. Each prefix denotes that the quantity's magnitude is tenfold larger than the preceding prefix. The gram is the base unit of mass, so the decagram is tenfold larger, with the hectogram one hundredfold larger and the kilogram one thousandfold larger (Deming 78). This method of identification works advantageously in two ways.