Lesson 2

Metric Units

In the metric system, all the units are related to one another by factors of ten as indicated by the prefixes. Factors of ten include 10, 100, 1,000, 1 million and so forth, as well as 1/10, 1/100, or 1/1,000. You should have already learned the most common of these prefixes. (They are also listed in example 15-a and 15-b in your workbook.) The unit can be meters, liters or grams.

The definitions of the prefixes give you the conversion relationships you need. One milliliter is 1/1,000th of a liter, or .001 liter. One centimeter is 1/100th of a meter or .01 meter. One kilogram is 1,000 grams. Since people usually talk about how many of the smaller units there are in the larger one, this example also shows that you can look at one liter as 1,000 milliliters, and one meter as 100 centimeters. You can use those relationships and often they will be easier.

You might prefer to think of these prefixes lined up from smallest to largest. Whatever unit you are working with (meters, liters or grams), the prefixes to the left on this scale represent fractions of that unit. Deci- is one-tenth, centi- is one-hundredth, milli- is one-thousandth, and micro- is one-millionth. The prefixes on the right side of this scale represent multiples of that unit. Deka- is ten times, hecto- is one hundred times, kilo- is one thousand times, and mega- is one million times.