map scale

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Map Scales
CGC1D
Introduction to Map Scales
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A map scale represents the
relationship between distance on the
map and distance in the real world.
Map scales are used to calculate:
• The distance between two points
• The size or area of a geographic feature,
such as a Province, City or Lake
Types of Map Scales
• Direct Statement Scale uses words to
describe what a distance on a map represents
in the real world
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For Example 1 cm = 10 kilometers
To determine the distance on a map with a direct
statement scale, measure the distance between the
two places. Calculate the distance based on the
scale.
For example, if you measured it to be 3cm between
the two places, you would calculate it like so:
1 cm = 10 km
(3 x 1) cm = (3 x 10) km
3 cm = 30 km
Therefore, the actual distance between the two
locations is 30 km.
Types of Map Scales
• Linear Scale is like a special kind of ruler that
is divided into units of distance
• With this type of map scale, you would need to
use the linear line as a reference to determine
how many kilometers one cm would represent
in real life.
Make a mark on your paper at the
right end of the scale
Move the mark from step three to 0 on
the line scale and measure the
remaining distance
Calculate the total distance between Kingston and Cornwall by adding together the two
distances you measured.
The distance between Kingston and Cornwall is 180 km.
Types of Map Scales
• Representative Fraction Scale is a ratio
where one unit on a map represents a specific
number of the same unit in the real world
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Represents
the
distance on
the map
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1:50 000
Represents
the distance
on the Earth’s
surface
For this example, 1 cm on the map
represents 50 000 cm in the real world or
0.5km)
Scale Conversions
1 km = 1000m
1 m = 100 cm
1 km = (1000 x 100) cm = 100 000 cm
Converting an R.F. Scale to a
Direct Statement Scale
To convert an R.F. scale to a direct
statement scale, divide the
denominator by 100,000, to change
into kilometers. Use the following
process:
1 cm = 50 000 cm
1 cm = (50 000 ÷ 100 000) km
1 cm = 0.5 km or 1 cm to 500 m
Converting a Direct Statement
Scale to R.F. Scale
To convert from a direct statement
scale back to an R.F. scale, multiply
the number of kilometres by 100 000
1 cm = 2.5 km
1 cm = (2.5 x 100 000) cm
1 cm = 250 000 cm or 1: 250 000
Examples
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Convert the representative fraction
to a direct statement 1: 250 000
Convert the direct statement scale to
an R.F. scale 1 cm to 5 km
Practice Map Scale
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From your textbook:
• Page 47
• Questions 1 to 10, 13