# 4.6.7: Appropriate Decimal Units for Metric Measurement

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## Metric Unit Length Conversions

Mustafa is planning to run a 5k race. In order to prepare for the race, he has been running each day. At the end of the first week, he runs 575 meters without stopping. He tries to figure out how that translates in kilometers so he converts 575 meters to kilometers. How many kilometers are equal to 575 meters?

In this concept, you will learn how to find equivalent metric measurements.

### Converting Using Decimal Numbers

Sometimes when you convert metric units you don’t have a whole number answer. When this happens, you end up with an answer that is a decimal.

Let's work through an example.

1 mm = ______ cm

Since you are converting a smaller unit to a larger unit, you are going to divide. There are 10 mm in one centimeter, so you are going to divide 1 by 10. You are dividing 1 whole into 10 parts.

1 ÷ 10 = 0.1 (one-tenth)

### Examples

Example 4.6.7.1

Earlier, you were given a problem about Mustafa and the race.

What is 575 meters in kilometers?

Solution

Convert 575 m to km

575 m = _______ km

First, determine if you are going from a smaller unit to a larger unit or a larger unit to a smaller unit.

Smaller to larger

Next, use the appropriate rule.

575 ÷ 1000

Then, write the value.

0.575

The answer is 0.575. Mustafa runs 0.575 kilometers.

Example 4.6.7.2

Convert 1 m to km.

1 m = ______ km

Solution

First, determine if you are going from a smaller unit to a larger unit or from a larger unit to a smaller unit.

Smaller to larger

Next, use the appropriate rule.

1 ÷ 1000 = 0.001

Then, write the value.

0.001

Example 4.6.7.3

Convert 2 m to km.

2 m = ______ km

Solution

First, determine if you are going from a smaller unit to a larger unit or from a larger unit to a smaller unit.

Smaller to larger

Next, use the appropriate rule.

2 ÷ 1000

Then, write the value.

0.002

Example 4.6.7.4

Convert 8 mm to cm.

8 mm = ______ cm

Solution

First, determine if you are going from a smaller unit to a larger unit or from a larger unit to a smaller unit.

Smaller to larger

Next, use the appropriate rule.

8 ÷ 10

Then, write the value.

0.8

Example 4.6.7.5

Convert 4 cm to m.

4 cm = ______ m

Solution

First, determine if you are going from a smaller unit to a larger unit or from a larger unit to a smaller unit.

Smaller to larger

Next, use the appropriate rule.

4 ÷ 100

Then, write the value.

0.04

### Review

Write each decimal conversion. Round to the nearest hundredth when necessary.

1. 1 mm = ______ cm
2. 5 mm = ______ cm
3. 10 mm = ______ cm
4. 15 mm = ______ cm
5. 8 cm = ______ m
6. 9 cm = ______ m
7. 11 cm = ______ m
8. 22 cm = ______ m
9. 12 m = ______ km
10. 8 m = ______ km
11. 22 mm = ______ cm
12. 225 mm = ______ cm
13. 543 mm = ______ cm
14. 987 mm = ______ cm
15. 1234 mm = ______ cm

To see the Review answers, open this PDF file and look for section 3.6.

### Vocabulary

Term Definition
Centimeter A centimeter is a very small unit of metric measure. A centimeter is one hundredth of one meter.
Kilometer A kilometer is a common metric unit of length that is equal to 1,000 meters.
Length Length is a measurement of how long something is. Examples of customary units of length are inches, feet, yards and miles.
Meter A meter is a common metric unit of length that is slightly larger than a yard.
Metric System The metric system is a system of measurement commonly used outside of the United States. It contains units such as meters, liters, and grams, all in multiples of ten.
Millimeter A millimeter is the smallest common metric unit of length.