Jon and Elly are making treat bags for their class party.

Jon brought 32 pieces of gum.

Elly brought 40 mints.

What is the greatest numberof equal treat bags they can make?

In this lesson you will learn how to find the

greatest common factor of two whole numbers

by listing factor pairs.

Let’s Review

Both 3 and 4 are factors of 12.

Factors are numbers multiplied together to equal a product.

3 x 4 = 12

For example:

3 x 4 is a factor pair.

Let’s Review

Let’s Review

Core Lesson

3 steps to finding the Greatest Common Factor

1. List the factor pairs.

2. Identify the common factors.

3. Find the biggest common factor. That is the Greatest Common Factor (GCF)

Core Lesson

Compare the factor pairs of 12 and 18.

1, 2, 3, and 6

2. Find common factors

3. Find GCF

1. List factor pairs

Jon and Elly are making treat bags for their class party.

Jon brought 32 pieces of gum.

Elly brought 40 mints.

What is the greatest numberof equal treat bags they can make?

Core Lesson

Find the greatest common factor of 32 and 40.

3. Find GCF 1, 2, 4, 8

1. List factor pairs

2. Find common factors

Core Lesson

Jon brought 32 pieces of gum.

4 gum 4 gum 4 gum 4 gum

4 gum 4 gum 4 gum 4 gum

Core Lesson

Elly brought 40 mints.

5 mints 5 mints 5 mints 5 mints

5 mints 5 mints 5 mints 5 mints

Core Lesson

5 mints 5 mints 5 mints 5 mints 5 mints 5 mints 5 mints 5 mints

The greatest number of equal treat bags Jon and Elly can make is 8.

4 gum 4 gum4 gum 4 gum4 gum 4 gum4 gum 4 gum

5 mints5 mints 5 mints 5 mints5 mints 5 mints5 mints 5 mints4 gum 4 gum 4 gum4 gum 4 gum4 gum 4 gum4 gum

Jon and Elly can combine bags.

In this lesson you have learned how to find the greatest

common factor of two whole numbers by listing factor pairs.