1. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 18. To find prime factors draw a factor tree. 18 Split 18 into a pair of factors. 2 9 2 is a prime number – so this branch is finished Split 9 into a pair of factors. 3 3 The prime factors of 18 are 2 x 3 x 3 The prime factors of 18 are 2 x 3 2

2. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 18. 18 Split 18 into a pair of factors. 3 6 3 is a prime number – so this branch is finished Split 6 into a pair of factors. 2 3 The prime factors of 18 are 2 x 3 x 3 The prime factors of 18 are 2 x 3 2

3. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 20. 20 Split 20 into a pair of factors. 2 10 Split 10 into a pair of factors. 2 5 The prime factors of 20 are 2 x 2 x 5 The prime factors of 20 are 2 2 x 5

4. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 20. 20 4 5 Split 4 into a pair of factors. 2 2 The prime factors of 20 are 2 x 2 x 5 The prime factors of 20 are 2 2 x 5

5. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 24. 24 2 12 2 6 The prime factors of 24 are 2 x 2 x 2 x 3 The prime factors of 24 are 2 3 x 3 2 3

6. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 24. 24 3 8 2 4 The prime factors of 24 are 2 x 2 x 2 x 3 The prime factors of 24 are 2 3 x 3 2 2

7. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of 24. 24 4 6 2 3 The prime factors of 24 are 2 x 2 x 2 x 3 The prime factors of 24 are 2 3 x 3 2 2

8. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall Find the prime factors of these numbers: Remember to find prime factors you draw a factor tree! 3016122228 12510064240144

9. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 12 2 6 2 3 3 4 2 2 The prime factors of 12 are 2x2x3 or 2 2 x 3

10. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 16 2 8 2 4 2 2 4 4 2 2 2 2 The prime factors of 16 are 2x2x2x2 or 2 4

11. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 30 2 15 3 5 30 5 6 2 3 The prime factors of 30 are 2 x 3 x 5

12. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 22 2 11 The prime factors of 22 are 2 x 11

13. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 28 2 14 2 7 28 4 7 2 2 The prime factors of 28 are 2x2x7 or 2 2 x 7

14. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 64 8 8 2 4 2 4 The prime factors of 64 are 2x2x2x2x2x2 or 2 6 2 2 2 2

15. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall The prime factors of 100 are 2x2x5x5 or 2 2 x 5 2 100 5 20 4 5 2 2

16. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall The prime factors of 125 are 5x5x5 or 5 3 125 5 25 5 5

17. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 240 24 10 2 5 4 6 The prime factors of 240 are 2 4 x 3 x 5 2 3 2 2

18. Objective: To write a number as a product of it’s prime factors. Prime Factors @lhmaths: Lesley Hall 144 12 3 4 3 4 The prime factors of 144 are 2 4 x 3 2 2 2 2 2