Teach GCSE Maths Scales and Maps

Teach GCSE Maths Scales and Maps © Christine Crisp "Certain images and/or photos on this presentation are the copyrighted property of JupiterImages and are being used with permission under license. These images and/or photos may not be copied or downloaded without permission from JupiterImages"

You will need squared paper to do the exercise.

A scale drawing would be used by a builder fitting kitchen cupboards. To find the measurements of the kitchen, we must multiply each 1 cm on the plan by 20. Length = 21  20 = 420 cm = 4 m 20 cm Width = 15  20 = 300 cm = 3 m This is a copy of 1 cm squared paper. Scale: 1 cm represents 20 cm 21 cm 15 cm Measurements of kitchen:

This is a copy of 1 cm squared paper. A scale drawing would be used by a builder fitting kitchen cupboards. Decide with your partner how wide the doorway is. Ans: There are 4 1 cm squares, so it is 4  20 = 80 cm The scale 1 cm represents 20 cm can be written as 1 : 20 Scale: 1 cm represents 20 cm 21 cm 15 cm

EXERCISE This is a scale drawing of a study on 1 cm squared paper. 2 cm represents 1 m 1. (a)How wide is the study on the plan? (b)How wide is the real study? (c)How wide is the doorway? desk (d)How wide is the large window? (e)What are the length and width of the desk? window

EXERCISE (a)On the plan the study is 6 cm wide. (b) 6 ÷ 2 = 3. The study is 3 m wide. (c)The doorway is 1 m wide. desk (d) The large window is 1·5 m wide. (e)The desk is 1·5 m long and 1 m wide. window Answers: This is a scale drawing of a study on 1 cm squared paper. 2 cm represents 1 m 1.

Street maps use a variety of scales. I found a local map booklet which had: Map 1. Scale: 3 Miles to 1 inch Map 2. Scale: 7 inches to 1 Mile How large would map 2 need to be to show both A and B ? How far apart are places A and B that are shown as 2 inches apart on Map 1 ? x x A B 2 inches 3  2 = 6 miles Ans: 7  6 = 42 inches There are about 39 inches in 1 metre so the map would be more than a metre across ! Ans:

Ans: Ans: 100 An Ordnance Survey map used by walkers might have a scale given as 1 : Can you work out what this means? Ans: 1 cm on the map represents cm But we don’t measure an afternoon’s walk in cms ! How many centimetres are there in 1 metre? How many metres are there in 1 kilometre? So, cm is  = 5 10 = 1 2 km 2 1

So, a map with a scale of 1 : means that 1 cm represents cm or ½ km. How far is a walk that covers 16 cm on the map? Ans: 16  ½ = 8 km

SUMMARY Scale drawings and maps show scales in many ways: e.g. 1. If 1 cm represents 20 cm, e.g. 2. If scale is 1 : km e.g cm on the plan represents 1 division represents 1 km, so 10 divisions on the map represents 10  1 = 10 km 10  20 = 200 cm 10  = cm = 5 km