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The Metric System. The USA is the only industrialized country that does not use the metric system as the official system of measurement. . (except for soda bottles). What do we use here? (US Customary Units - Based on old English system) Length:. 1 foot =. 12 in. 1 yard =. 3 feet.
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The USA is the only industrialized country that does not use the metric system as the official system of measurement. (except for soda bottles)
What do we use here? (US Customary Units - Based on old English system) Length: 1 foot = 12 in 1 yard = 3 feet 1 mile = 5280 feet Why?... "A Mile ſhall contain eight Furlongs, every Furlong forty Poles, and every Pole ſixteen Foot and a half." -English Act of Parliament, 1593 There are many more (point, nautical mile, etc.) -And this is just for length...
Area, volume (fluid vs. dry), weight... 1 acre = 43560 sq ft 1 tablespoon = 3 teaspoons 1 fl oz = 2 tablespoons 8 fl oz 1 cup = 1 pint = 2 cups 1 quart = 2 pints 1 gallon = 4 quarts = 128 fl oz 1 pound = 16 (dry) oz 1 ton = 2000 lbs Hard to use: no obvious connection between them – you just have to memorize them ALL
The metric system was designed to be easy to use, and consistent for the whole world: Everything based on a single base unit, and prefixes that multiply or divide that unit by powers of 10(not 2, 16, 5280) meter(all length units will have “meter” in them) Base unit of length? Powers of 10? Prefix deca- 101 = 10 hecto- 102 = 10 x 10 = 100 kilo- 103 = 10 x 10 x 10 = 1,000 104 = 10 x 10 x 10 x 10 = 10,000 mega- 106 = 10 x 10 x 10 x 10 x 10 x 10 = 1,000,000 million giga- 109 = 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 1,000,000,000 billion 1012 = 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 1,000,000,000,000 trillion
rule: 10-x = 1 10x Negative powers of 10: Prefix ( 102 = 10 x 10 = 100 ) 1 = 1 = 1 . 102 10 x 10 100 10-2 = = .01 centi- one one-hundredth 1 . = 1 . 10 x 10 x 10 1000 = .001 milli- 10-3 = one one-thousandth 1 = 1 . 10 x 10 x 10 x 10 x 10 x 10 1,000,000 10-6 = micro- one one-millionth = .000001
Here they all are: The nice thing about these prefixes, is that they can be used for all kinds of measurement units, and they always mean the same thing
Other base (and derived) units: length: meter mass: gram = 1/1000 kilogram (kg = about 2.2 lbs) square meter, m2 area: volume: cubic meter, m3 liter (= 1 dl3 ) liquids only time: second temperature: degrees Celsius
Because everything is in powers of 10, to interconvert between units you just have to move the decimal point... 1 km = 103 m = 1000 m 45 km = 45,000 m move the decimal point 3 places to the right 45.987 km = 45,987 m 0.45 km = 450 m 1 mm = 10-3 m = .001 m move the decimal point 3 places to the left 4956 mm = 4.956 m 57 mm = .057 m (Always check to make sure you went the right direction.)