Year 6 - Maths
Describe the relationship between scale factors and perimeters of two shapes
Area, perimeter, position and direction
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will explain how to calculate the area of a parallelogram and a triangle. They will describe the relationship between scale factors and side lengths. They will describe positions in all 4 quadrants.
Lesson Summary
You will learn to describe the relationship between scale factors and side lengths and perimeters of two shapes.
Key Notes
- If the lengths of the sides of a shape have been doubled, the perimeter will be double.
- If the side lengths of a shape are multiplied by the same factor the perimeter will be multiplied by the same factor.
- The number which all the sides have been multiplied by is called a scale factor.
Vocabulary To Learn
- Perimeter: Perimeter is the distance around a two-dimensional shape.
- Scale factor: A scale factor is the multiplier between similar shapes that describes how large one shape is compared to the other.
- Similar: Two shapes are similar when one shape can become the other after a resize, flip, slide or turn.
Common Mistakes To Avoid
- Pupils may remember to scale one of the sides (or pairs of sides) of a shape but forget to scale the others.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
If the lengths of the sides of a shape have been doubled, the perimeter will be double. If the side lengths of a shape are multiplied by the same factor the perimeter will be multiplied by the same factor.
2. Use this key word in a maths sentence and explain it clearly. 'Perimeter'
Perimeter is the distance around a two-dimensional shape. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils may remember to scale one of the sides (or pairs of sides) of a shape but forget to scale the others. Correction: Focus attention on what it means when a shape is similar, drawing on examples and non-examples to support learners to understand how scaling affects all side lengths.
More Lessons In This Unit
- Draw and complete simple shapes by plotting positions on the full coordinate grid Study Guide
- Draw and translate simple shapes on the full coordinate grid Study Guide
- Explain how to calculate the area of a parallelogram Study Guide
- Explain how to calculate the area of a triangle Study Guide
- Reflect simple shapes in the axes on a full coordinate grid Study Guide
- Solve problems involving area and perimeter Study Guide
- Solve problems involving missing coordinates Study Guide
- Use the area of a parallelogram formula to calculate unknown measurements Study Guide
- Use the area of a triangle to calculate unknown measurements Study Guide
Browse all guides in the Year 6 Maths guide library.