Common factors worksheet
A free common factors worksheet: factor lists, Venn diagrams, the greatest common factor and common multiples, with an answer key.
Download the free common factors worksheet (PDF)
Common factors worksheet
What’s on the worksheet
31 questions: list the factors of 6 pairs and find what they share, fill in 2 Venn diagrams, find 12 greatest common factors and 6 sets of common multiples, then 5 problems. The key fills in every list.
- 31 questions on common factors, sized for US Letter paper
- 2 pages of questions plus an answer key on the last page
- Written for grades 4–6, matching Common Core 4.OA.B.4, 6.NS.B.4
- Name and date lines at the top, and room to show the work
Sample questions from this worksheet
- List the factors of 12 and 18, then the common factors.
- Fill in the Venn diagram for the factors of 12 and 20.
- GCF of 27 and 36
- Write the first two common multiples of 4 and 6.
- List all the common factors of 24, 36 and 48.
- Simplify 16/40 by dividing by the GCF.
Practice common factors online
Between worksheets, a few minutes on screen keeps the skill fresh:
- common factors practice: pick the number that divides both.
- GCF and LCM calculator: common factors in bold.
- common factors lesson: Venn diagrams and a quiz.
If factor lists come out short, the usual cause is listing one at a time. Ask your child to list in pairs from both ends before looking for the shared numbers.
Preview the worksheet and answer key
Make a new common factors worksheet
Need another page for extra practice, a retake or a second group in class? The free Mathify Kids test maker builds a fresh common factors worksheet with different numbers every time. Choose how many questions, print it with its own answer key, or let your child take it on screen and see the score straight away.
Common factors: a worked example (Common factors of 12 and 18)
- Factors of 12: 1, 2, 3, 4, 6, 12.
- Factors of 18: 1, 2, 3, 6, 9, 18.
- The numbers in both lists are 1, 2, 3 and 6. The greatest is 6.
How to use it at home and in class
At home
List factors in pairs from both ends: 1 × 18, 2 × 9, 3 × 6. Stop when the pairs meet and nothing gets missed. Ten problems a day works better than a whole sheet at once. Mark them together with the answer key, then ask your child to explain one they got wrong: finding the mistake themselves is where the learning happens.
In class
Use the first row as a warm-up, a full page for independent practice, or five questions as an exit ticket. For a retake or a second group, make a new version with the test maker so every child gets different numbers.
Mistakes to watch for
- Missing a factor by listing one at a time instead of in pairs.
- Mixing in multiples, like 36, which is bigger than both numbers.
What to practice before and after common factors
- Before: prime and composite numbers. If this sheet is a struggle, go back a step.
- After: GCF and LCM word problems, once this one is mostly right.
- Learn it first: the common factors lesson and the factors and multiples chart.
More factors & multiples worksheets
Last reviewed
Questions parents ask
What is the difference between common factors and the GCF?
Common factors are all the numbers that divide both numbers. The GCF is the greatest of them.
What grade is this common factors worksheet for?
It is written for grades 4–6 and matches Common Core standards 4.OA.B.4, 6.NS.B.4.
Can I get a different version of this common factors worksheet?
Yes. Use the free Mathify Kids test maker to make a new common factors worksheet with different numbers every time. You choose how many questions, and every version comes with its own answer key.