How Do You Find the Greatest Common Factor?

Are your students learning to find the greatest common factor of 2 or more numbers? This 6th-grade math skill is important when working with fractions, especially when finding common denominators. 

If it has been a while since you’ve taught students how to find the GCF, no worries! Teach Starter has you covered with a poster you can use and then pass on to your students to keep as a reference tool.

To find the greatest common factor (GCF) of two or more numbers, you can use the “divide and conquer” method.

The divide and conquer method involves:

• Listing the factors of each number
• Finding the common factors among the numbers
• Determining which common factor is the largest

How to Make the Most of Your GCF Reference Sheet

1. Print the poster and display it in your classroom for students to reference when doing independent work.
2. Print the poster, slip it into a clear sleeve and use it in your guided groups as a reminder.
3. Print the poster, slide it into a clear sleeve and hang it on a ring as a reference tool for a learning center. 

We’ve also come up with bonus ways to turn posters into interactive tools that really make your lessons stick! 

📝 Create a fill-in-the-blank worksheet by removing selections of text.  

📂 Place copies in students’ homework folders for reference. 

💻 Provide posters as digital resources for virtual students. 

🧠 Test students’ memories by showing them the poster, then hiding it and having them tell you what they remember.

✅ Incorporate posters into your lesson wrap-up: students write on a sticky note what they learned from the lesson and place it on the poster. 

Before You Download

This resource prints as a PDF. Please use the dropdown menu to choose between the full-color, black and white, or editable Google slides version.

This resource was created by Jillian Sloane, a teacher in West Virginia and a Teach Starter Collaborator. 

Spend more time lesson-doing and less time lesson-planning when you grab these activities and teaching resources too! 

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Greatest Common Factor and the Distributive Property Worksheets

Determine the GCF and use the distributive property to express the sum of two whole numbers as a multiplication equation with a common factor.

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Greatest Common Factor – Task Cards

Practice how to find the greatest common factor (GCF) with this set of 24 task cards.

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Greatest Common Factor – Mini Book

Learn different strategies to find the greatest common factor with this mini-book.