The distance between your school and Andy's house is 1760 ft. In the metric system all units are related to each other by factors of 10, so it is very easy to divide and multiply units in the metric system. Also, you don't have to memorize many different conversion factors. Prefixes are added to metric units to show how many powers of 10 each unit represents compared to the basic units. So to convert from 80 cm to meters, you just divide by 100 and get 0.8 m.
Metric units are the units most commonly used in physics.
For Playground Physics you too will use metric units. American units of length and mass are more familiar than metric units for most people in the United States. Metric units can be related to American units the same way feet can be related to a mile. If you don't know how long a meter really is, converting the meter to a unit you are more familiar with might help. A flag pole is 3.50 meters tall.