3. Prime Number – An integer whose only factors are 1 and itself 2, 3, 5, 7,11, 13, 17, 19

4. Prime Factor Tree for 60 Write 60 at the top of the page 60 60 = prime number 2 x 30 2 2 30 15 35 30 = prime number 2 x 15 15 = prime number 3 x prime number 5 60 is all the prime numbers 2 x 2 x 3 x 5 multiplied together

5. Draw factor trees for: 24 and 60

6. FACTOR TREES 24 60 4 6 4 15 2223 2 235 24 = 2 x 2 x 2 x 360 = 2 x 2 x 3 x 5

7. 24 = 2 x 2 x 2 x 3 60 = 2 x 2 x 3 x 5 HCF = 2 x 2 x 3 = 12

8. Find the HCF for 16 and 30

9. FACTOR TREES 16 30 4 4 2 15 2222 35 16 = 2 x 2 x 2 x 230 = 2 x 3 x 5

10. 16 = 2 x 2 x 2 x 2 30 = 2 x 3 x 5 HCF = 2

11. 1. 30 and 45 2. 45 and 20 3. 40 and 80 4. 36 and 24 5. 32 and 16 HCF = 15 HCF = 5 HCF = 40 HCF = 11 HCF = 16

12. Complete the minute glass activity Complete Minute Glass Activity

13. Lowest Common Multiple LCM

14. Multiple of 5 5, 10, 15, 20, 25, 30.... Multiple of 8 8, 16, 24, 32, 40, 48..... Multiple of 42 42, 84, 126, 168, 210...

15. The LCM of two or more numbers is the smallest number that is a multiple of each of the numbers.

16. 24, 48, 72, 96, 120, 144,…. 60, 120, 180, 240, 300,....

17. Find the lowest common multiple of 4 and 18 4, 8, 12, 16, 20, 24, 28, 32, 36, 40……. 18, 36, 54, 72……. LCM = 36

18. Find the Lowest Common Multiple 1.15 and 6 2.9 and 12 3.24 and 6 4.4 and 18 5.15 and 16 LCM = 30 LCM = 36 LCM = 24 LCM = 36 LCM = 240

19. Complete the minute glass activity Complete Minute Glass Activity

20. 24 60 Venn Diagram 24 = 2 x 2 x 2 x 3 60 = 2 x 2 x 3 x 5 2 2 3 2 5 HCF = 2 x 2 x 3 = 12 LCM = 2 x 2 x 2 x 3 x 5 = 120 HCF is the region of intersection 2 x 2 x 3 = 12 LCM is all the numbers in the circles multiplied together 2 x 2 x 2 x 3 x 5=120

21. Find the HCF and LCM of the following: 1. 6 and 15 2. 20 and 30 3. 14 and 42 4. 24, 30 and 54 Answers: 1.HCF = 3, LCM = 30 2.HCF = 10, LCM = 60 3.HCF = 14, LCM = 42 4.HCF = 6, LCM = 1080