1. Write factor pairs for each number. Use divisibility tests to help you!40 72 57
1 x 40
1 x 72
1 x 57
2 x 20
2 x 36
3 x 19
4 x 10
3 x 24
5 x 8
4 x 18
6 x 12
8 x 9

2. Write factor pairs for each number. Use divisibility tests to help you!12 20 37
1 x 12
1 x 20
1 x 37
2 x 6
2 x 10
PRIME
3 x 4
4 x 5

3. PRIME NUMBERS
A whole number with exactly 2 factors, 1 and itself 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

4. Make a prime factor tree for each number.24 60 4 x 6 6 x 10 2 x 2 x 2 x 3 2 x 3 x 2 x 5
24 = 2 x 2 x 2 x 3
60 = 2 x 2 x 3 x 5
24 = 23 x 3
60 = 22 x 3 x 5

5. You can use prime factorizations to find the GCF or to simplify fractions.24 60 4 x 6 6 x 10 2 x 2 x 2 x 3 2 x 3 x 2 x 5
GCF
2 x 2 x 3 = 12
2460 2
2 x 2 x 2 x 3 5
2 x 2 x 3 x 5

6. Make a prime factor tree for each number to find the GCF.36 54 6 x 6 6 x 9 2 x 3 x 2 x 3 2 x 3 x 3 x 3
36 = 2 x 2 x 3 x 3
GCF
2 x 3 x 3 = 18
54 = 2 x 3 x 3 x 3

7. Make prime factor trees for each number
Make prime factor trees for each number. Use the prime factorizations to find the GCF and to simplify the fraction. 40 56 4 x 10 2 x 28 2 x 2 x 2 x 5 4 x 7 2 x 2
4056 5
2 x 2 x 2 x 5 = = 7
GCF x 2 x 2 = 8
2 x 2 x 2 x 7

8. List the factors of 15. 15
1 x 15
3 x 5
List the multiples of 15.
15, 30, 45, 60, 75, …

9. List the first 5 multiples of each number.12
12, 24, 36, 48, 60 16
16, 32, 48, 64, 80 24
24, 48, 72, 96, 120

10. Use the LCM to get a common denominator.
7 12 28 12
12, 24, 36, 48, 60 = 48
5 16 15 16
16, 32, 48, 64, 80 = 48 24
24, 48, 72, 96, 120

11. Use the LCM to get a common denominator.12
12, 24, 36, 48, 60
5 16 15 16
16, 32, 48, 64, 80 = 48
9 24 18 24
24, 48, 72, 96, 120 = 48

12. Use the LCM to get a common denominator.
5 12 10 12
12, 24, 36, 48, 60 = 24 16
16, 32, 48, 64, 80
11 24 11 24
24, 48, 72, 96, 120 = 24

13. List the factors of 32. 32
1 x 32
2 x 16
4 x 8

14. Make a prime factor tree for 32.4 x 8 2 x 16 2 x 2 2 x 4 4 x 4 2 x 2 2 x 2 x 2 x 2
32 = 2 x 2 x 2 x 2 x 2
32 = 25

15. Use the prime factorization to simplify
12 32 12 32 2 x 6 2 x 16 2 x 3 4 x 4 2 x 2 x 2 x 2
12 = 2 x 2 x 3
3 8
What is the GCF?
32 = 2 x 2 x 2 x 2 x 2 4

16. List factor pairs to find the GCF.18 30
1 x 18
1 x 30
GCF = 6
2 x 9
2 x 15
3 x 6
3 x 10
5 x 6
18 30
3 10
Use the GCF to simplify:
÷ 6
÷ 6

17. Write the expressions using exponents.
2 x 3 x 3 x 5 x 5 =
2 x 32 x 52
5 x 5 x 5 x 7 x 7 =
53 x 72

18. Find the LCM.
3 8 15 8
8, 16, 24, 32, 40 = 40
4 10 16 10
10, 20, 30, 40 = 40