Map Scale

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Map Scale

• See Making Connections, pages 44-49

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What is map scale? Map scale shows the
relationship between distance on a map and the
actual distance on the earths surface. It can be
shown three ways Statement scale Line
scale Representative fraction scale
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Statement Scale Uses words, e.g., 1 cm to 10 km 1
cm on the map represents 10 km in the real world
http//academic.brooklyn.cuny.edu/geology/powell/s
cale_module/map_east_small.jpg
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Line Scale A ruler or line on a map divided into
units of distance.
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Representative Fraction (RF) Scale Scale is shown
as a ratio Eg., 150 000 This means that one unit
on the map represents 50 000 of the same units in
the real world. Doesnt matter what units as long
as they are the same.
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Scale Conversion If two places on a map are 1 cm
apart and the RF scale is 150 000, that means
they are 50 000 cm apart in the real world. But
what is 50 000 cm?!!!?? You have to convert to a
statement scale.
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Conversion example (RF scale to statement
scale) RF scale is 150 000 Steps 1 cm 50 000
cm You want to change the 50 000 cm into
something meaningful kilometers 1 km 1000 m
(kilo means 1000) 1 m 100 cm 1 km
(1000x100) cm 100 000 cm Therefore, 1 cm
(50 000 100 000) km 1 cm 0.5 km (or 1 cm
500 m)
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Conversion example (statement scale to RF
scale) Statement scale is 1 cm to 2.5 km
Steps 1 cm 2.5 km 1 cm (2.5 x 100 000) cm 1
cm 250 000 cm Since the units are now the same
on both sides of the equation, this can be
written as 1250 000.