of gas in the tank, he or she could represent the total number of miles it is possible to
drive based on how much gas is put into the tank. This can be expressed as 20g,in
which gstands for the number of gallons in the tank. For example, if someone bought
10 gallons of gas to reach a destination (10 gallons 20 miles/gallon), the traveler
can go about 200 miles (the gallons in the top and bottom of the equation cancel each
other out, leaving miles).
Another example involves cars and mileage. If the traveler drives down a highway
at a steady rate of 65 miles per hour, the driver can determine how long it will take to
get to a destination, especially if he or she knows how many miles it is to that destina-
tion. The equation is mileage divided by 65 miles per hour (m/65). For example, if the
traveler is going 650 miles, the (650 miles)/(65 miles per hour) equals 10 hours (the
miles in the top and bottom of the equation cancel each other out, leaving hours).
What is the scale of a map?
Most travel, street, or highway maps show a measurement scale, usually in terms of
miles and kilometers. To determine a straight line (horizontal) distance on a map,
take a piece of paper and mark the origin and destination as tick marks on the paper.
Then measure the “distance” between the tick marks based on the map scale to find
the distance in miles or kilometers. 417
EVERYDAY MATH
Our planet has been divided into 24 time zones—indicated by somewhat erratic lines that run north and south—
which are used by most people to set their clocks and coordinate schedules. Taxi/Getty Images.