1. Factors of 15
1, 15
3, 5

2. Factors of 18
1, 18
2, 9
3,6

3. Factors of 12
1, 12
2, 6
3,4

4. Find the factors of (5 mins)
1,6 2,3
1,8 2,4
1,16 4
1,21 3,7
1, ,12 3,8 4,6 6 8 16 21 24 28 17 20 40
100
1, ,14 4,7
1,17
1, ,10 4,5
1, ,20 4,10 5,8
1,100 2,50 4,25 5,20 10,10

5. Factor Trees 18 3 6 2 3

6. Factor Trees 12 3 4 2 2

7. Factor Trees

8. Now do factor trees on: 6 8 16 21 24 28 17 20 40 100 = 2  3
Now write the product of primes for each question
= 2  2  2 = 23
= 2  2  2  2 = 24
= 7  3
= 2  2  2  3 = 23  3
= 2 x 2 x 7 = 22 x 7 =
= 2 x 2 x 5 = 22 x 5
= 2 x 2 x 2 x 5 = 23 x 5
= 2 x 2 x 5 x 5 = 22 x 52