Finding the Greatest Finding the Greatest Common FactorCommon Factor

Finding the Greatest Finding the Greatest Common FactorCommon Factor

Grade 5Grade 5

Lesson Objectives

• 6.B.1.c Identify the greatest common factor

3.A.1.a Use technology tools, including software and hardware, from a range of teacher-selected options to learn a new content or reinforce skills

Think Backwards…

•Find Factors•Circle Common Factors•Group Greatest Factor

Step 1: Find the Factors

• 24 – 1,2,3,4,6,8,12,24• 36 – 1,2,3,4,6,9,12,18,36

Step 2: Circle Common Factors

• 24 – 1,2,3,4,6,8,12,24• 36 – 1,2,3,4,6,9,12,18,36

Step 3: Group the Greatest Factor

• 24 – 1,2,3,4,6,8,12,24• 36 – 1,2,3,4,6,9,12,18,36

The Greatest The Greatest Common Factor of 24 Common Factor of 24

and 36 is…and 36 is…

The Greatest The Greatest Common Factor of 24 Common Factor of 24

and 36 is…and 36 is…

1212

Now let’s try finding the GCF

Find the GCF of 12 and 24

• Step 1: Find the factors

• 12 – 1,2,3,4,6,12• 24 –

1,2,3,4,6,8,12,24

Find the GCF of 12 and 24

• Step 2: Circle the common factors

• 12 – 1,2,3,4,6,12• 24 –

1,2,3,4,6,8,12,24

Find the GCF of 12 and 24

• Step 3: Group the greatest factor

• 12 – 1,2,3,4,6,12• 24 –

1,2,3,4,6,8,12,24

The Greatest The Greatest Common Factor of 12 Common Factor of 12

and 24 is …and 24 is …

The Greatest The Greatest Common Factor of 12 Common Factor of 12

and 24 is …and 24 is …

1212

Your turn!• Find the Greatest Common Factor

of 16 and 20.

• Remember…Find Factors, Circle Common, Group Greatest!

The Greatest The Greatest Common Factor of 16 Common Factor of 16

and 20 is…and 20 is…

The Greatest The Greatest Common Factor of 16 Common Factor of 16

and 20 is…and 20 is…

44

Are you ready?Are you ready?Are you ready?Are you ready?

Let's try some more!Let's try some more!