Statement scale
1 cm represents 2 km
Written in words and easy to interpret.
🎯 Learning Objectives
By the end of this lesson, you should be able to:
- Recognise a statement scale.
- Recognise a ratio or representative-fraction scale.
- Read a line scale.
- Explain that both sides of a ratio scale must use the same unit.
🤔 Start with the Idea
Scales can be written in different ways. They may look different, but each one communicates the same idea: how drawing measurements correspond to real measurements.
📖 Three Common Forms
Ratio scale
1 : 200 000
Both measurements use the same unit.
Line scale
0 ├────┤ 5 km
A marked bar that can be measured directly.
A ratio scale of 1 : 200 000 means 1 cm on the map represents 200 000 cm in real life, not 200 000 km.
🎮 Explore the Scale
Change the map or drawing length and the scale value. Notice how the real distance changes proportionally.
🧠 Let’s Think Together
Interpret the ratio scale 1 : 50 000.
Both sides use centimetres, so 1 cm on the map represents 50 000 cm in real life.
50 000 cm÷ 100500 m
Answer: 1 cm represents 500 m.
✏️ Practice Questions
Build confidence- Write 1 cm represents 4 km as a statement scale.
- At scale 1 : 100 000, how many kilometres does 1 cm represent?
- Name the type of scale shown as a marked bar from 0 to 10 km.
✅ Check your answers
- 1 cm represents 4 km
- 1 km
- Line scale
⚠️ Common Mistakes
- Using different units on the two sides of a ratio scale.
- Multiplying when the question requires division, or dividing when it requires multiplication.
- Leaving out the unit or using a linear unit for an area.
- Rounding too early in a multi-step calculation.
🎯 Exam Focus
Write what the scale means before calculating. Show unit conversions clearly, keep full calculator values until the final step, and include the correct unit in the answer.
📌 One-Minute Summary
- A scale connects a drawing or model to the corresponding real object.
- Use multiplication when moving from a drawing measurement to a real measurement.
- Use division when working backwards from real size to drawing size.
- Ratio scales require the same unit on both sides.
- Area changes by the square of the linear scale factor.