Do you participate in track like the boys pictured here? If not, you may have attended a track meet. The boys in the picture are running a 100-meter sprint. Running events in track are named for their distance.

### What Is Distance?

**Distance** is the length of the route between two points. The distance of a race, for example, is the length of the track between the starting and finishing lines. In a 100-meter sprint, that distance is 100 meters.

### SI Unit for Distance

The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers.

### Using Maps to Measure Distance

Maps can often be used to measure distance. The map in the **Figure** below shows the route from Jordan’s house to his school. You can use the scale at the bottom of the map to measure the distance between these two points.

**Q:** What is the distance from Jordan’s house to his school?

**A:** The distance is 2 kilometers.

For a video explaining how to find map distances, including curved distances, go to this URL: http://www.youtube.com/watch?v=t-ckG3ncM8E

### Summary

- Distance is the length of the route between two points.
- The SI unit for distance is the meter.
- The scale of a map can be used to find the distance between different locations.

### Explore More

Find an online map tool, like the one at the following URL, that calculates the distance between any two points you select. Make a list of several pairs of locations between which you want to know the distance. Use the map scale to estimate the distance between locations in each pair. Then use the tool to find the actual distances. http://www.freemaptools.com/measure-distance.htm

### Review

- Define distance.
- What is the SI unit for distance? Give an example of something you might measure in this unit.
- Runners in different lanes on an oval racetrack have different starting marks. Explain why.
- On the map in the
**Figure**above, what is the distance between Jordan’s house and the park?