Help your students build confidence and fluency with prime numbers and factorisation using our structured and supportive Prime Factorisation Worksheets! This hands-on resource is designed to strengthen students’ understanding of how composite numbers can be broken down into their prime components. With scaffolded tasks that gradually increase in complexity, students will practise creating factor trees, identifying prime factors, and writing complete prime factorisations with accuracy and understanding.

Students begin by using factor trees to break down composite numbers into their prime building blocks. From there, they match numbers to their correct prime factorisations, identify missing components, and finally write their own complete prime factorisations for a variety of numbers. This step-by-step structure ensures that students are not only practising the skill but also deepening their number sense, reinforcing their understanding of factors, primes, and multiplication relationships.

Prime Factorisation Worksheets are ideal for use during your number unit, as part of numeracy rotations, or for targeted intervention. The resource supports repeated exposure to the factorisation process, helping students build fluency and accuracy over time. Whether used independently, in pairs, or during teacher-led small groups, these worksheets provide an engaging way to explore one of the most fundamental skills in number theory.

Key Learning Outcomes:

• ✅ Understand the difference between prime and composite numbers
• ✅ Use factor trees to break down composite numbers
• ✅ Recognise and apply prime factorisation accurately
• ✅ Strengthen multiplication and divisibility understanding
• ✅ Build fluency and confidence in number structure and relationships

What’s Included:

• Four scaffolded worksheet sections designed to build understanding and fluency
• Section 1: Complete factor trees to find the prime factors of composite numbers
• Section 2: Match numbers to their correct prime factorisations
• Section 3: Identify and fill in missing prime factors
• Section 4: Write the full prime factorisation of given numbers
• Space provided for working out and checking answers through multiplication

Materials Needed:

• Printed worksheets (on paper or card for durability)
• Pencils or pens
• Optional: highlighters or coloured pencils to track branches of factor trees
• Whiteboard for modelling strategies and checking answers as a class

How to Use:

1. Begin with a class review of prime and composite numbers, and what it means to factorise.
2. Model how to create a factor tree and check the final factorisation by multiplying the prime factors.
3. Complete Section 1 as a guided activity to practise building factor trees.
4. Use Section 2 for reinforcement – matching composite numbers to their prime factor breakdowns.
5. In Section 3, challenge students to identify missing prime factors based on known number properties.
6. Wrap up with Section 4 – where students demonstrate independence in writing complete prime factorisations.

Ideas for Classroom Use:

• 💡 Use during number and algebra units to build foundational number knowledge
• 💡 Include in maths rotations for independent reinforcement of key skills
• 💡 Display sample factor trees on your maths wall as student-generated reference
• 💡 Create a partner challenge where students take turns giving each other numbers to factorise
• 💡 Use as pre- and post-assessment to measure understanding of prime factorisation

Teacher Tips:

• 💛 Provide multiplication charts and prime number reference lists for support
• 💛 Encourage students to use colour to trace each branch of their factor trees
• 💛 Reinforce the importance of checking – have students multiply their prime factors to verify their work
• 💛 Extend students by giving them numbers with specific characteristics, such as having three unique prime factors

Prime Factorisation Worksheets provide a clear and structured approach for exploring the prime foundations of numbers – helping students build number sense, accuracy, and confidence as they break composite numbers down to their core.