L12-3 Notes: Length in Metric System Chapter 12 L12-3 Notes: Length in Metric System

Vocabulary A meter is the basic unit of length in the metric system. The metric system is a decimal system of weights and measures.

Metric Units of Length Unit Model Benchmark 1 millimeter (mm) thickness of a dime 25mm ≈ 1in 1 centimeter (cm) half the width of a penny 2.5cm ≈ 1in 1 meter (m) width of a doorway 1m ≈ 1.1yd 1 kilometer (km) six city blocks 6.2km ≈ 1 mi

The segment below is 2. 5 centimeters or 25 millimeters long The segment below is 2.5 centimeters or 25 millimeters long. This is about 1 inch in customary units.

Use Metric Units of Length 1. Write the metric unit of length that you would use to measure the width of a paper clip. Compare the width of a paper clip to the models described above. The width of a paper clip is greater than the thickness of a dime, but less than half the width of a penny. So, the millimeter is an appropriate unit of measure.

Use Metric Units of Length 2. Write the metric unit of length that you would use to measure the height of a desk. Since the height of a desk is close to the width of a doorway, the meter is an appropriate unit of measure.

Use Metric Units of Length 3. Write the metric unit of length that you would use to measure distance across Indiana. Since the distance across Indiana is much greater than 6 city blocks, this is measured in kilometers.

On Your Own… Write the metric unit of length that you would use to measure each of the following. 1. width of a CD 2. thickness of a nickel 3. height of a cereal box