The lengths in a scale drawing are in proportion to the actual lengths of an object.

We often use a ratio to show the scale of a drawing

If we have a scale of 1:5 all of the lengths in the scale drawing are 5 times smaller than in real life

If a map has a scale of 1:5000 to find the actual distance between two points we would have to multiply the distance on the map by 5000

If two points are 10 cm apart on the map they are 10 cm × 5000 apart in real life

10 cm × 5000 = 50000 cm

50000 cm = 500 m

**Example: A map has a scale 1:20000The actual distance between two towns is 12kmFind the distance between the two towns on the mapGive your answer in cm**

We can convert 12 km into cm first

To convert km to metres we times by 1000

To convert metres into centimetres we times by 100

12 km = 12000 m = 1200000 cm

The real life distance is 20000 times bigger than the distance on the map

To find the distance on the map we need to divide the real distance by 20000

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