Prime and Composite Numbers Worksheet: Find the Factors
Understanding whether a number is prime or composite starts with one essential skill: finding its factors. This free printable worksheet helps students practice listing all factors of a number and then classifying it as prime, composite, or neither. Designed for upper elementary learners, this activity builds strong number sense while reinforcing a foundational math concept.
What Students Will Practice
With this worksheet, students will:
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List all factors of a given number
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Identify whether a number is prime, composite, or neither
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Recognize why the number 1 does not fit into either category
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Strengthen factor fluency through repeated practice
Why This Skill Matters
Prime and composite numbers play an important role in later math topics, including:
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multiplication and division
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greatest common factor (GCF)
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least common multiple (LCM)
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fraction simplification
By learning to find factors first, students build the reasoning skills they’ll need for more advanced problem solving.
How to Use This Worksheet
This worksheet works well for:
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independent practice
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small-group instruction
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math centers
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homework or review
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intervention or reteaching
An answer key is included to support teachers, parents, and tutors.
Who This Worksheet Is For
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Grade level: 3rd grade (with 4th grade review use)
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Skill focus: Factors, prime numbers, composite numbers
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Math topic: Factors and multiples
