OCR GCSE EXAM MATHS 12.3 MAPS,SCALE DRAWINGS AND BEARINGS A+GRADED EXAM

Exercise 1 1 The scale on a map is 1 : 400. What is the actual distance (in metres) between two points that are 15 cm apart on the map? 12.3 MAPS, SCALE DRAWINGS AND BEARINGS ©Cambridge University Press and OCR 2020 2 2 Work out the real distance in km that a map distance of 15mm would represent if the map scale was 1 : . WORKED EXAMPLE A map scale is given as 1cm : 20km. What is the actual distance on the ground that on the map measures 5cm? Solution 1cm : 20km Now multiply by 5. 5cm : 100km The answer is 100 km. 3 A map scale is 1cm : 500m. What is the actual distance (in km) on the ground that measures 10cm on the map? 4 The scale of a map is 1cm : 100km. Find the length on the map that represents the real length of 560km. 5 Two towns are 2.5km apart. If they are drawn on a map using a scale of 1cm : 0.5km, how far apart will they be on the map? WORKED EXAMPLE 10km on the ground is represented by 5cm on a map. What is the scale of the map in the form 1 : n, where n is a whole number? Solution 5cm : 10km Change the right-hand side to cm. Use 1km = 1000m and 1m = 100cm. So, 1km = 1000 × 100cm = cm. So, 10km = cm × 10 = cm. 5cm : cm As there are cm on both sides, we can remove the units. 5 : Divide both sides by 5. The answer is 1 : . 6 A map has a scale of 5cm to 1km. What is the scale of the map written in the form 1 : n, where n is a whole number?