Idiot\'s Guides Basic Math and Pre-Algebra

346 Appendix E

Notice that the units of length, mass, and capacity are linked. The liter is the capacity of a

cube 10 centimeters wide by 10 centimeters long by 10 centimeters high, connecting length and

volume to capacity. The gram is the mass of a cubic centimeter of water, which associates mass

with volume and length and capacity.

From the basic units, you can break into smaller units or build into larger units, always multiply-

ing or dividing by powers of ten. The naming of those units follows the same system of prefixes

whether the base unit is meter, liter, or gram. Here are the prefixes and some ideas to help you

imagine some of the commonly used units.

Smaller

1

1,000

milli- Millimeter: approximately the thickness of 10 sheets of

paper

Milligram: the mass of a grain of salt

Milliliter: about 20 drops of water

1

100

centi- Centimeter: approximately the diameter of a pencil

eraser, or the diameter of a AAA battery

Centigram: the approximate mass of a U.S. dollar bill, or

about two raisins.

Centiliter: about half a teaspoon

1

10

deci- Decimeter: approximately the length of a crayon

Decigram: two nickels

Deciliter: about one-fourth of a can of soda

Larger

10 deca-

(or deka-)

Decameter: a long bus or train car

Decagram: about half the mass of a small mouse

Decaliter: approximately the capacity of a teapot

100 hecto- Hectometer: about a city block

Hectogram: the mass of an orange

Hectoliter: about the capacity of a small refrigerator

1,000 kilo- Kilometer: about 2.5 laps on a stadium track

Kilogram: mass of a dictionary or large textbook

Kiloliter: the capacity of about eight large trash cans