MAP SCALE

Map Scales

Scale:

Shows the relationship between the distance on a map and the actual distance on the earth’s surface

Ex:1:50,000 means: 1cm on the map = 50 000 cm on the earth

There are 3 different types of scale:1. Direct Statement Scale (1cm = .5 km)2. Line Scale 3. Representative Fraction (1:50,000)

.5 km

1cm

Types of Scales

1. Direct Statement Scale:

Uses words to show the relationship of the scale

1cm to 1km or 1cm=1km

Question???

If you have measured the distance between Hamilton and Toronto and found it to be 25 cm on the map and the direct statement reads 1cm to 2 km.

How far would it be in km?

The answer is….

50 km

1 cm/25cm = 2 km/X1xX = 2x25X-50cm

2. Line Scale:

Is a ruler that is divided into units of

distance

1st measure the distance on the map and 2nd compare it to the scale to calculate the distance

3. Representative Fraction (R.F.):

Is usually shown as a ratio 1:50 000

1 unit on the map represents 50 000 of the same units on the earth’s surface

1: 50 000

The 1st term Is always 1Represents distance on the mapRepresents same unit of measure as the

2nd term

The 2nd term 50 000 represents the distance on the earthRepresents same unit of measure as the

1st term

First term is always 1 (represents the distance on the map)

50 000 represents the distance on the earths surface

Represents the same unit of measurement on both terms of the ratio

Metric Conversions

1 km = 1000m 1 m = 100cm 1km = 100 000 cm

1. Converting R.F. to direct statement - divide by 100 000 (move the decimal 5 places to the left)

Example: 1: 50 000 1cm = 50 000cm 1cm= (50 000/100 000)km 1cm= 0.5km

2. Converting direct statement to R.F. - multiply by 100 000 (move decimal 5 places to the right)

Example: 1cm to 2.5km 1 cm = (2.5 km x 100 000 cm) 1 cm = 250 000 cm (1: 250 000)

Scale Exercise

Direct Statement Representative Fraction

Line Scale

1cm to 2.5 km

1: 350 000

0 40 km

Applying Scale…

A B - 1cm to 100 km

A

B - 1: 250 000

A 0 20 km

B- 1 cm