*Contributor: Rachel Lewis. Lesson ID: 12176*

Measuring big items (like whales and distances) and small items (like fingernails and ants) requires different units of measurement. The metric system makes it easier to convert large and small units!

categories

subject

Math

learning style

Visual

personality style

Lion, Beaver

Grade Level

Intermediate (3-5)

Lesson Type

Skill Sharpener

The metric system uses prefixes to show different values, making it easier to convert measurements than using inches and feet and yards. How do you convert between millimeters, centimeters, meters, and kilometers?

How do you measure length?

What tool would you use to find the length of an object? Tell a teacher or parent your definition of "length" and how you measure length.

In the United States, people use rulers and tape measures to measure inches, feet, and yards. In other countries around the world, the *metric system* is used. In the metric system, length is measured in *meters*.

The metric system uses three standard units: *liters*, *grams*, and *meters*.

*Liters*are used to measure*volume*. You can use liters to measure how much milk is in the carton.*Grams*measure the*mass*, or*weight*, of an object like a loaf of bread or a bag of sugar.*Meters*measure*length*and*distance*. We can use meters to measure the length of a bicycle.

*Prefixes* are attached to the beginning of the standard unit to change its meaning. Prefixes show a change in size.

To measure length, we can use three main prefixes:

- kilo-
- centi-
- milli-

We can add kilo- to the beginning of meter to measure large distances. Kilometers are larger than meters. In fact, there are 1000 meters in 1 kilometer. We can add centi- and milli- to the beginning of meters to measure smaller objects. There are 100 centimeters in one meter and 1000 millimeters in one meter.

To learn more about the differences between kilometers, meters, centimeters, and millimeters, read Metric Length from MathIsFun.com.

On a sheet of paper, create your own meter conversion chart. Use the chart below as a guide.

- How many millimeters make up a meter?
- How many centimeters are in a meter?
- How many meters make up a kilometer?

## millimeters |
## meter |
||||||

## centimeters |
## meter |
||||||

## kilometer |
## meter |
||||||

Can you think of your own examples of things to measure with kilometers, meters, centimeters, and millimeters? Share your ideas with a parent or teacher.

Next, use your conversion chart to complete the activities in the *Got It? *section.