Year 7 - Maths
HCF or LCM
Properties of number: factors, multiples, squares and cubes
Study Hub
Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils develop their understanding of factors and multiples, then extend this knowledge to learn general divisibility tests for integers and develop strategies to determine the highest common factor and lowest common multiple of two or more integers.
Lesson Summary
You will learn to use the prime factorisation of two or more positive integers to efficiently find either the highest common factor or lowest common multiple, depending on the context of the question.
Key Notes
- It may be necessary to find the HCF in real world situations
- It may be necessary to find the LCM in real world situations
- It is important to identify which of the LCM and HCF are needed in real world situations
- The LCM and HCF can be found in a variety of different contexts
Vocabulary To Learn
- HCF: HCF is an abbreviation for highest common factor.
- LCM: LCM is an abbreviation for lowest common factor.
Common Mistakes To Avoid
- When using a Venn diagram students often mix up HCF & LCM.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
It may be necessary to find the HCF in real world situations. It may be necessary to find the LCM in real world situations.
2. Use this key word in a maths sentence and explain it clearly. 'HCF'
HCF is an abbreviation for highest common factor. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: When using a Venn diagram students often mix up HCF & LCM. Correction: Encourage students to check the reasonableness of their answer.
More Lessons In This Unit
- Calculating integers from their prime factor expressions Study Guide
- Checking understanding of factors, multiples, squares and cubes Study Guide
- Checking understanding of prime numbers Study Guide
- Divisibility tests for 2 and 3 Study Guide
- Divisibility tests for 4 and 8 Study Guide
- Divisibility tests for 5 and 10 Study Guide
- Divisibility tests for 6 and 9 Study Guide
- Expressing an integer as a product of its prime factors Study Guide
- Highest common factor Study Guide
- Listing factors Study Guide
- Listing multiples Study Guide
- Lowest common multiple Study Guide
- Power notation Study Guide
- Powers and roots using a calculator Study Guide
- Problem solving with factors, multiples, squares and cubes Study Guide
- Securing understanding of factors, multiples, squares and cubes Study Guide
- Square and cube numbers Study Guide
- Square and cube roots Study Guide
Browse all guides in the Year 7 Maths guide library.