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## Basic geometry and measurement

### Course: Basic geometry and measurement>Unit 5

Lesson 6: Converting to larger or smaller

# Metric units of length review (mm, cm, m, & km)

Review the size of millimeters, centimeters, meters, and kilometers and how to convert between them.  Then, try some practice problems.

## Summary of metric units of distance

KilometerMeterCentimeterMillimeter
$1$$1000$$100,000$$1,000,000$
$\frac{1}{1000}$$1$$100$$1000$
$\frac{1}{100,000}$$\frac{1}{100}$$1$$10$

## What is distance?

Distance measures length. For example, the distance of a road is how long the road is.
In the metric system of measurement, the most common units of distance are millimeters, centimeters, meters, and kilometers.

### How big are metric units of distance?

A paper clip is about $1$ millimeter thick.
A fingernail is about $1$ centimeter wide.
The length of a guitar is about $1$ meter.
A kilometer is equal to $1000$ meters. It is a little over half of a mile.

## Practice set 1: Estimating distance

Problem 1A
Identify the most reasonable unit to measure the distance from New York to California.

Want to try more problems like this? Check out this exercise.

## Converting larger units to smaller units

To convert larger units to smaller units we multiply the number of larger units by the green conversion factor for the appropriate smaller units.
Example: Converting meters to centimeters:

## Converting smaller units to larger units

To convert smaller units to larger units we divide the number of smaller units by the purple conversion factor for the appropriate larger units.
Example: Converting meters to kilometers:
$5$ meters $=$