Scale drawings
Objective. Convert between drawing and actual lengths using a scale.
- 1. Learn
- 2. Worked example
- 3. Practice
- 4. Feedback
- 5. Continue
Learn: the key idea
A scale drawing represents a real object or space at a reduced or enlarged size, with a scale showing the relationship between drawing lengths and actual lengths. A scale written as 1:100 means every 1 cm on the drawing represents 100 cm, or 1 m, in reality. To convert a drawing length to an actual length, multiply by the scale factor; to convert an actual length back to the drawing, divide by the scale factor. For example, a wall measuring 3 cm on a 1:50 scale drawing represents an actual length of 3×50=150 cm.
Worked example
A scale drawing of a garden uses a scale of 1:200. If a path measures 8 cm on the drawing, use the scale to find its actual length in metres.
- 1Identify the scale factor: 200.
- 2Multiply the drawing length by the scale factor: 8×200=1600 cm.
- 3Convert centimetres to metres by dividing by 100: 1600÷100=16.
- 4State the actual length with correct units.
Answer: 16 m
Concept mastery
Based on your past attempts at this lesson — the question types to practise again come first.
Complete a practice set to see your concept breakdown here.
Practice
Practice happens on its own screen, one question at a time. Answers stay hidden until you submit yours, and you can stop and pick up at the same question later.
Start practisingCommon mistake. Pupils sometimes divide instead of multiplying when converting from drawing size to real size, making actual objects seem smaller than the drawing. Always multiply the drawing length by the scale factor to find the real size.
Your progress
Tick each step as you finish it. Your exact reading position is saved automatically, so Continue drops you back on the same line.
0 of 5 steps complete
Your place saves automatically as you read.