Units Lesson

​In the United States, as well as two other countries Liberia and Myanmar, we use the "customary" measurement system.

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This system uses inches, feet, yards, and miles for distance.

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We use ounces and pounds for weight. (lbs and oz)

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For volume or capacity we use fluid ounces, cups, pints, quarts, and gallons.

Countries all over the world from Sudan to Mexico to Germany use the metric system.

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This system uses meters for length.

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They use grams for weight.

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For volume or capacity they use liters.

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They also use prefixes to note small or large quantities of each measurement.​

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What do these prefixes mean?

Let's just focus on these three prefixes right now:

Kilo = 1,000 times a measurement. Kilometer = 1,000 meters

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Centi = 1/100 (a hundredth) of a measurement​

Centimeter = 1/100 meter

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Milli = 1/1000 (a thousandth) of a measurement

Millimeter​

Remember we only use these prefixes with the metric system! There is no "kilo-inch" or "milli-pound".