Map Scale Conversions
Definitions
Map Scale:
Is a ratio which helps us understand the relationship between the distance on a map,
and the real distance on the surface of the earth that it represents.
Representative Fraction:
Is a map scale in the format 1 : 250 000.
This means that 1 unit (ex: 1 cm) on the map represents 250 000 units (ex: 250 000 cm
or 2.5 km) on the ground. Note that whichever units you choose must remain the same
for both sides of the fraction/ratio
Remember:​ 100 000 cm = 1km
Direct Statement:​ Is a map scale in written format
For example: 1cm = 2.5km
Converting between representative fraction and direct statement is easy to do.
Go through the following examples to better understand.
Practice
(With Teacher) Jacob wants to ride his bike to Mohammed’s house. Looking at a map,
he uses a ruler and sees that his house measures 3.7cm away from his house. How far
away does he actually live? (1cm = 1km)
(Practice) Nicole uses a series of straight lines following the roads, to determine how
far Rachel lives from her. Using the diagram below, along with a representative fraction
of 1:750 000, determine the distance on the road between the two houses.
(With Teacher) Given a direct statement scale of 4cm = 20km, what is the proper format
to write this direct statement scale?
(With Teacher) Matt measures a distance on the map to the Canoe club as being 9cm. If
the direct statement scale of the map is 1cm = 2.5km, how far is the Canoe Club on the
earth’s surface?
(With Teacher) The direct statement scale for a map shows 4cm = 0.2km. What is the
map’s representative fraction scale?
(Practice) The direct statement scale for a map shows 1cm = 5km. What is the map’s
representative fraction scale?
(Practice) You know that the distance between your home and school is 7km. What is
the distance on a map with a scale of 1:750 000?