Find the Greatest Common Factor (GCF) of 12 and 8.

12×××

Step 1: Make a “T-Chart” for both numbers.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

1 122 63 4

8××

1 82 4

The GCF of 12 and 8 is 4

8

Find the Greatest Common Factor (GCF) of 16 and 24.

16×××

Step 1: Make a “T-Chart” for both numbers.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

1 162 84 4

24××

1 242 12

The GCF of 16 and 24 is 8

×3×4 6

66

16

Find the Greatest Common Factor (GCF) of 30 and 48.

30×××

Step 1: Make a “T-Chart” for both numbers.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

1 302 153 10

48××

1 482 24

The GCF of 30 and 48 is 6

×3×4 12×5× 8

810

Find the Greatest Common Factor (GCF) of 32 and 40.

32×××

Step 1: Make a “T-Chart” for both numbers.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

1 322 164 8

40××

1 402 20

The GCF of 32 and 40 is 8

×4×5

18

912

Find the Greatest Common Factor (GCF) of 18, 36, and

45.18×××

Step 1: Make a “T-Chart” for all 3 numbers.

Step 2: Look for common factors between all 3 numbers.

Step 3: Circle the greatest factor that all 3 numbers have in common.

Step 4: This is the GCF.

12 93 6

36××

1 362 18

The GCF of 18, 36, and 45 is 9

×3×4

9

45××

1 453 15×5

6×6

4

You can find the Greatest Common Factor of a fraction’s numerator and

denominator ,too.

9××

Step 1: Make a “T-Chart” for numerator and the denominator.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

1 93 3

12××

1 122 6×3

What is the GCF of ?912

The GCF of is 3.912

You can find the Greatest Common Factor of a fraction’s numerator and

denominator ,too.

Step 1: Make a “T-Chart” for numerator and the denominator.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

What is the GCF of ?2530

The GCF of is 5.2530

610

25××

1 255 5

30××

1 302 15×3×5

You can find the Greatest Common Factor of a fraction’s numerator and

denominator ,too.

Step 1: Make a “T-Chart” for numerator and the denominator.

Step 2: Look for common factors between both numbers.

Step 3: Circle the greatest factor that both numbers have in common.

Step 4: This is the GCF.

What is the GCF of ?2432

The GCF of is 8.2432

8

24×××

1 242 123 8

36××

1 322 16×4

×4 6

Use “T-Charts” to find the GCF.

4

12××

1 122 6×3

1. 12 and 30

10

30××

1 302 15×3×5 6

15××

1 153 5

2. 15 and 45

9

45××

1 453 15×5

GCF: 6 GCF: 15

Use “T-Charts” to find the GCF.

6

18××

1 182 9×3 12

36××

1 362 18×3×4 9

21××

1 213 7

4.

35××

1 355 7

GCF: 18 GCF: 7

18363

.

×6 6

2135

Use “T-Charts” to find the GCF.

27××

1 273 9

5. 27 and 30

10

30××

1 302 15×3 8

24××

1 242 12×3×4 6

6. 24 and 36

6

12

36××

1 362 18×3×4 9× 6

GCF: 3 GCF: 6

Use “T-Charts” to find the GCF.

7. 12, 15, and 21

21××

1 213 7

GCF: 3

15××

1 153 5

4

12××

1 122 6×3