1.5 HOW DO WE USE SCALE ON A MAP?

MAP SCALE
1. a map is a reduced representation of a real area.
2. MAP SCALE is the relationship (or ratio) between distance on a map and the corresponding distance in the real ground.
3. NUMERIC OR RATIO SCALE is expressed as a fraction (i.e. E:1/200,000 or E:1:200,000. It means that 1 cm on the map represents 200,000 cm on the real ground or 2,000m or 2km)
4. GRAPHIC SCALE (LINEAR OR BAR SCALE) shows the equivalent distance on a bar divided into equal segments, usually 1cm. Each piece or segment of the bar represents a given distance, as labelled.
HOW TO USE SCALE TO CALCULATE DISTANCES
1. USING NUMERIC SCALE
  1. 1. First we change numeric scale (i.e. E:1:11900000 > 1cm in the map is 11900000 cm or 119000m or 119 km in the real world ).
  2. 2. Then we have to measure in centimetres with a ruler the distance we wish to calculate (i.e. 6 cm)
  3. 3. Finally we do the calculations: 6 x 119 km = 714 km
2. USING GRAPHIC SCALE
  1. 1. First we measure how long one segment of the graphic scale is on your ruler (i.e. 16 cm on the bar is 5000 km).
  2. 2. Then we have to measure with a ruler the distance we wish to calculate in centimetres (i.e. 8 cm)
  3. 3. Finally we do the calculations: divide the total distance measured by the length of one segment of the scale (8:16=0,5 segments) > 0,5x 5000km= 2,500km
  4. OTHER FORM: we can use a piece of paper down on the map and mark it with the distance we wish to calculate or with the segments of the bar.

Resource summary

	Created by Benito Román Guerrero Blanco over 7 years ago