What is it
Number theory at KS3 covers prime numbers, prime factorisation, and using index notation to express powers and roots, building a deeper understanding of how numbers are built from their prime building blocks.
Why it matters
Prime factorisation is the tool behind finding HCF and LCM efficiently with larger numbers, and index laws here are the direct foundation for algebraic manipulation and standard form, both heavily tested at GCSE.
Exam tip
Practise prime factor trees until breaking any number under 100 into its prime factors becomes second nature — this single skill underpins several other topics.
Related topics
Want help mastering Number Theory?
Tell us about the student's goals and confidence — we'll design a personalised plan.