(U. S. BUREAU OF STANDARDS)
THE METRIC SYSTEM.
The fundamental unit of the metric system is the meter (the unit of length). From this the units of mass (gram) and capacity (liter) are derived. All other units are the decimal sub-divisions or multiples of these. These three units are simply related, so that for all practical purposes the volume of one kilogram of water (one liter) is equal to one cubic decimeter.
| Prefixes. | Meaning. | Units. |
| Milli- | = one thousandth 1-1000 .001 | Meter for length. |
| Centi- | = one hundredth 1-100 .01 | |
| Deci- | = one tenth 1-10 .1 | |
| Unit | = one 1. | Gram for mass. |
| Deka- | = ten 10-1 10. | |
| Hecto- | = one hundred 100-1 100. | Liter for capacity. |
| Kilo- | = one thousand 1000-1 1000. |
The metric terms are formed by combining the words "Meter," "Gram" and "Liter" with the six numerical prefixes.
Length
| 10 milli-meters mm | = | 1 centi-meter | c m |
| 10 centi-meters | = | 1 deci-meter | d m |
| 10 deci-meters | = | 1 meter (about 40 inches) | m |
| 10 meters | = | 1 deka-meter | d k m |
| 10 deka-meters | = | 1 hecto-meter | h m |
| 10 hecto-meters | = | 1 kilo-meter (about 5/8 mile) | k m |
Mass.
| 10 milli-grams. m g | = | 1 centi-gram | c g |
| 10 centi-grams | = | 1 deci-gram | d g |
| 10 deci-grams | = | 1 gram (about 15 grains) | g |
| 10 grams | = | 1 deka-gram | d k g |
| 10 Deka-grams | = | 1 hecto-gram | h g |
| 10 hecto-grams | = | 1 kilo-gram (about 2 pounds) | k g |
Capacity.
| 10 milli-liters. m l | = | 1 centi-liter | c l |
| 10 centi-liters | = | 1 deci-liter | d l |
| 10 deci-liters | = | 1 liter (about 1 quart) | l |
| 10 liters | = | 1 deka-liter | d k l |
| 10 deka-liters | = | 1 hecto-liter (about a barrel) | h l |
| 10 hecto-liters | = | 1 kilo-liter | k l |
The square and cubic units are the squares and cubes of the linear units.
The ordinary unit of land area is the Hectare (about 2-1/2 acres).