Common Factors

List the factors of 12 & 20, then identify the greatest common factor.
12-
20-
GCF=

• 12- 1, 2, 5, 7  20-10, 20, 30, 40 GCF 10
• 12-1, 12, 24, 36  20-20, 40, 60, 80 GCF 40
• 12-2, 4, 6   20-1, 10, 20 GCF 20
• 12-1, 2, 3, 4, 6, 12  20-1, 2, 4,5,10, 20 GCF 4

What is the greatest common factor of 10 and 25?

• 5
• 1
• 10
• ^₁

What are the factors of 16 and 24?

• 16-1, 3, 6, 12, 16
  24-1, 2, 4, 6, 24
• 16-1, 2, 4, 8, 16
  24-1, 2, 3, 4, 6, 8, 12, 24
• 16-16, 32, 48, 54
  24-24, 48, 72, 86
• 16- 1, 2, 16
  24-1, 2, 12, 24

Which is a factor of 15?

• 2
• 3
• 4
• 6

Tags

CCSS.4.OA.B.4

What is the greatest common factor of 8 and 10?

• 1
• 3
• 4
• 2

Select ALL the Common FACTORS of 16 and 40:

• 2

• 4

• 9

Select the Common FACTOR for 14 and 21:

• 2

• 7

• 3

Answer explanation

Factors are whole numbers that can be multiplied together to produce another whole number.

7x2=14

7x3=21

Tags

CCSS.4.OA.B.4

Select the Common FACTORS of 12

and 30:

• 2, 3, 4, 6

• 1, 6, 8,12

Answer explanation

Factors are whole numbers that can be multiplied together to produce another whole number.

2x6=12

3x4=12

Tags

CCSS.4.OA.B.4

Select a Common FACTOR of 6 and 9:

• 3

• 6

• 9

Answer explanation

Factors are whole numbers that can be multiplied together to produce another whole number.

3x3=6

3x3=9

The number 372 is divisible by....

• 2 and 6

• 2, 3 and 4

• 2, 3, 6 and 9

• 2 and 4