Greatest Common Factor Worksheet

Welcome to our Greatest Common Factor Worksheets page.

Here you will find our selection of worksheets involving finding the greatest common factor of 2 or 3 numbers up to 100.

We have a range of sheets at different levels of difficulty.

Greatest Common Factor Worksheets

On this page we have worksheets for finding the greatest common factor of 2 or 3 numbers up to 100.

We also have a link to our Greatest Common Factor Calculator which will quickly and easily find the greatest common factor between 2 or more numbers, and also show you the working out along the way.

Using these greatest common factor worksheets will help your child to:

  • understand what the greatest common factor is;
  • find the greatest common factor between two numbers up to 100.

The Greatest Common Factor - what is it?

First of all let us think about what a factor is.

A factor is a number which divides into another number with no remainder.

In other words, you can multiply a factor by a whole number to get to the number it is a factor of.

  • 12 = 3 x 4, so 3 and 4 are both factors of 12.
  • 25 = 5 x 5 so 5 is a factor of 25
  • 60 = 12 x 5, so 5 and 12 are both factors of 60.

You will also note that 1 is a factor of all integers.

Now a common factor is a number that several numbers have in common.

And the Greatest Common Factor between two numbers is the largest number that is a factor of both numbers.

And the Greatest Common Factor between lots of numbers, is the largest factor that all the numbers have in common.

The Greatest Common Factor is the same as the Highest Common Factor, and the Greatest Common Divisor.

It is often abbreviated to the GCF.

If there are no other common factors, then the gcf is 1 (as 1 is a factor of all positive integers.)

If the greatest common factor of two integers is 1, the integers are said to be coprime.

How to find the Greatest Common Factor (or GCF) - two methods

So how can we find the greatest common factor?

There are a number of different ways to do this, but our worksheets use two of the most common:

  • listing all the factors method
  • prime factorization method

Greatest Common Factor Help

If you want to learn more about the Greatest Common Factor and how each of the methods above works, come and visit our Definition of Greatest Common Factor page.

We have lots of worked examples showing you how to find the greatest common factor using different methods.

Greatest Common Factor Calculator

Our Greatest Common Factor calculator will tell you the highest common factor between 2 or more numbers.

It will also list the factors of each of the numbers and tell you whether they are coprime or not.

Greatest Common Factor Worksheets

We have split our Greatest Common Factor worksheets into two main sections: the A group and the B group.

The A group uses the listing all the factors of both numbers to find the greatest common factor.

The B group uses the prime factorization method to find the greatest common factor.

The A and B sheets are supported sheets and provide a framework for finding the gcf.

In the third section, there are also harder sheets for more advanced students which can be used with either method.

In our final worksheet section, we have some combined Greatest Common Factor and Lowest Common Multiple worksheets.

Greatest Common Factor Worksheets - Listing all the Factors Method

Greatest Common Factor Worksheets - Prime Factorization Method

Greatest Common Factor Worksheets - Harder Section

This section is for students who are already proficient at finding the GCF and do not need any extra support or prompts.

Least Common Multiple and Greatest Common Factor Worksheets

The Least Common Multiple and Greatest Common Factor are often taught alongside each other.

These sheets involve finding both the LCM and GCF on the same sheet.

The first two sheets are easier and keep the numbers for the LCM and GCF separate.

The third and fourth sheets involve finding the LCM and GCF of the same numbers.

The fourth sheet involves 3 numbers rather than 2.

Least Common Multiple and Greatest Common Factor Riddles

Looking for something a little different to get children to apply their knowledge of GCF and LCM?

Using riddles is a great way to explore and apply your LCM and GCF knowledge by solving problems.

The aim is to find the correct answer out of 6 choices from following the clues.

There are 2 riddles on each sheet.

Looking for some more factor and multiples sheets?

We have worksheets to help you understand more about factors and multiples.

They are aimed at a 4th/5th grade level.

More Recommended Math Worksheets

Take a look at some more of our worksheets similar to these.

Greatest Common Factor Calculator

Our Greatest Common Factor calculator will tell you the highest common factor between 2 or more numbers.

It will also list the factors of each of the numbers and tell you whether they are coprime or not.

Least Common Multiple Worksheets

We have a range of worksheets on how to find the least common multiple of two or three numbers.

The sheets vary in difficulty, and are suitable for 6th grade and up.

Least Common Multiple Calculator

Our Least Common Multiple Calculator will find the lowest common multiple of 2 or more numbers.

It will also show you the working out using a choice of two different methods.

There are also some worked examples on the page with explanation of how it works.

5th and 6th Grade Fractions Worksheets

Here you will find a range of more complex Fraction Worksheets for 5th and 6th graders.

At 5th Grade level, children are introduced to adding and subtracting fractions with different denominators. They know and can use equivalent fractions, and can multiply a fraction by whole numbers, as well as adding mixed numbers.

Using these sheets will help your child to:

  • add and subtract fractions and mixed numbers;
  • understand how to multiply fractions by a whole number;
  • understand how to multiply two fractions together, including mixed fractions;
  • understand the relationship between fractions and division;
  • know how to divide fractions and mixed fractions;
  • convert decimals to fractions.
 

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How to Print or Save these sheets

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Need help with printing or saving?
Follow these 3 easy steps to get your worksheets printed out perfectly!

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