4. Maps: reality in miniature What is the scale of a map? Maps are always much smaller than the territor y they represent. To show how much reality has been reduced in size, a scale is used . Scale is the ratio between the size of a territor y in reality and the size it occupies on the map. The scale on a map can be either numerical or graphic. A numerical scale is expressed as a fraction . The numerator (the number on the top of the fraction) represents a unit of measurement on the map, for example 1 cm. The denominator (the number on the bottom of the fraction) indicates its size in reality. This scale means that 1 cm on the map is equivalent to 200,000 cm in reality : 1 Distance on the map 200,000 Distance in reality The numerical scale can be written in three ways: 1 200,000 1/200,000 1:200,000 A graphic scale is expressed by a straight line divided into equal segments, usually of 1 cm. Figures are usually expressed in kilometres and indicate the actual size of each segment. This scale shows that 1 cm on the map is equivalent to 20 km in reality. 0 20 40 60 Small and large scale maps A territor y on a map can be represented with dif ferent scales depending on the level of detail required . (12) For example: WORK WITH THE IMAGES Look at the two maps of Ibiza. Which map has less detail? Look at the scale. How many times has reality been reduced in size on the map with less detail? And on the other map? Reach a conclusion. Which maps have greater detail: those with large or small scales? Map A has a scale of 1:200,000. This means the distance in real life is reduced 200,000 times. Map B has a scale 1:1,250,000. This means the distance in real life is reduced 1,250,000 times. B A 12. Ibiza (A and B) on two maps of different scales Explain what the scale on a map is for. Scales are also often used on floor plans. Imagine you are going to redecorate your bedroom with new furniture. Would a plan to scale be useful? Why? K E Y Q U E S T I O N S 16
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