Units Lesson

Prefixes for our Units

By Mr. Duback

What units do we use for measurement?

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

​

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

​

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

​

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

What about the rest of the world?

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

​

This system uses meters for length.

​

They use grams for weight.

​

For volume or capacity they use liters.

​

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

​

Multiple Choice

What does the prefix kilo- stand for?

• 100

• 1,000,000

• 1,000

• 1/1000

Multiple Choice

What does the prefix centi- stand for?

• 100

• 1,000

• 1/100

• 1/10

Multiple Choice

What does the prefix milli- stand for?

• 1,000

• 10

• 1/100,000

• 1/1,000

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

​

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

Centimeter = 1/100 meter

​

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".

Poll

Let's take the metric unit for mass which is "gram". Do you recognize seeing this somewhere? First answer the poll, then we can share out.

• Yes

• No