Prime Factors
Year 6 students learn to express whole numbers as products of prime factors using factor trees, strengthening their understanding of divisibility and number structure.
What You Need to Know
Key Concept Diagram
A prime number has exactly two factors: 1 and itself
Every composite number can be written as a unique product of prime factors
Factor trees break a number down step by step until all branches are prime
The prime factorisation of a number is always the same regardless of starting factors
Key Vocabulary
Prime number
A number greater than 1 with no factors other than 1 and itself
Composite number
A number with more than two factors
Factor tree
A diagram used to find the prime factors of a composite number
Prime factorisation
Writing a number as a product of its prime factors
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
Which of the following is a prime number?
Question 2
What is the prime factorisation of 36?
Question 3
Using prime factorisation, which two numbers share the prime factor 5?
Key Concepts Summary
- ●A prime number has exactly two factors: 1 and itself
- ●Every composite number can be written as a unique product of prime factors
- ●Factor trees break a number down step by step until all branches are prime
- ●The prime factorisation of a number is always the same regardless of starting factors