Printable Greatest Common Factor Worksheets
Printable greatest common factor worksheets for 4th and 5th grade, with an answer key on every sheet. The sets below cover 5 different skills, so you can start where your child actually is. Available as speed drills, visual guides, and word problems.
Targeted Practice by Skill
GCF by listing factors
Format 1
GCF by listing factors
Format 2
GCF by listing factors
Format 3
GCF by prime factorization
Format 1
GCF by prime factorization
Format 2
GCF by prime factorization
Format 3
GCF of two numbers to 100
Format 1
GCF of two numbers to 100
Format 2
GCF of two numbers to 100
Format 3
GCF of two numbers to 500
Format 1
GCF of two numbers to 500
Format 2
GCF of two numbers to 500
Format 3
GCF of three numbers
Format 1
GCF of three numbers
Format 2
GCF of three numbers
Format 3
About Greatest Common Factor
What this skill is
Greatest Common Factor (GCF) is the largest shared factor that divides two or more numbers evenly (e.g., GCF of 12 and 18 is 6).
When children learn it
GCF calculations are taught in 4th and 5th grade, supporting fraction simplification standards.
Teaching Tips
- List all factors for both numbers, circle shared common factors, select largest.
- Use prime factorization trees.
Common Mistakes
- Selecting a common factor that is not the greatest (choosing 2 instead of 6 for 12 and 18).
- Confusing GCF with LCM.