The Metric System

1. The Metric System from Industry Week, 1981 November 30

2. Used in nearly every country in the world, the Metric System was devised by French scientists in the late 18th century. The goal of this effort was to produce a system that used the decimal system rather than fractions as well as a single unified system that could be used throughout the entire world.

5. Prefixes

6. Converting with the Metric System • When converting within the metric system it is simply a measure of moving the decimal in the appropriate direction.

7. Converting with the Metric System • King Henry Drinks Milk During Castle Meetings • Kilo Hecto Deca Meter Deci Centi Milli • 1000 100 10 1 .1 .01 .001 • 1000 m = ______ km • .001 hg = ______ dg • 42.7 L = _____ cL

8. Things to remember • The short forms for metric units are called symbols, NOT abbreviations • Metric symbols never end with a period unless they are the last word in a sentence. • RIGHT: 20 mm, 10 kg • WRONG: 20 mm., 10 kg. • Metric symbols should be preceded by digits and a space must separate the digits from the symbols • RIGHT: the box was 2 m wide • WRONG: the box was 2m wide

9. Things to remember • Symbols are always written in the singular form • RIGHT: 500 hL, 43 kg • WRONG: 500 hLs, 43 kgs • BUT: It is correct to pluralize the written out metric unit names: 500 hectoliters, 43 kilograms • The compound symbols must be written out with the appropriate mathematical sign included • RIGHT: 30 km/h, 12 cm/s • WRONG: 30 kmph, 30 kph (do NOT use a p to symbolize “per”) • BUT: It is ok to write out “kilometers per hour”

10. Things to remember • The meaning of a metric symbol is different depending on if it is lowercase or capitalized • mm is millimeters (1/1000 meters) • Mm is Megameters (1 million meters)