1 Factors Stage 4 - Year 7 Press Ctrl-A ©2009 – Not to be sold/Free to use

2 Factors of a number are numbers which we can divide into the number without a remainder Example: List the factors of Factors 42

3 Factors of a number are numbers which we can divide into the number without a remainder Example: List the factors of Factors 42

4 Factors of a number are numbers which we can divide into the number without a remainder Example: List the factors of Factors 42 6

5 Circle Common Factors To find the Highest Common Factor (HCF) of two numbers: 1. 1.List the set of factors of each number Find the largest number common to both. Example: Find the HCF of 12 and 20. Factors of 12: 1, 2, 3, 4, 6, 12. Factors of 20: 1, 2, 4, 5, 10, 20. Highest Common Factor 42 H ighest C ommon F actors

6 Circle Common Factors To find the Highest Common Factor (HCF) of two numbers: 1. 1.List the set of factors of each number Find the largest number common to both. Example: Find the HCF of 30 and 25. Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30. Factors of 25: 1, 5, 25. Highest Common Factor 42 H ighest C ommon F actors

7 Circle Common Factors To find the Highest Common Factor (HCF) of two numbers: 1. 1.List the set of factors of each number Find the largest number common to both. Example: Find the HCF of 16 and 24. Factors of 12: 1, 2, 4, 8, 16. Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24. Highest Common Factor 42 H ighest C ommon F actors