Master HCF and LCM
Find the highest common factor and lowest common multiple of two numbers. Practice with instant feedback.
What are HCF and LCM?
Highest common factor and lowest common multiple
HCF (also GCD) is the largest integer that divides both numbers. LCM is the smallest positive integer that is a multiple of both. Use prime factors or Euclid’s algorithm for HCF, then LCM = ab / HCF.
HCF and LCM Rules
Key steps
Follow the method
HCF (also GCD) is the largest integer that divides both numbers. LCM is the smallest positive integer that is a multiple of both. Use prime factors or Euclid’s algorithm for HCF, then LCM = ab / HCF.
Check your answer
Compare with the multiple-choice options and use inverse operations to verify.
HCF and LCM Examples
Worked examples
Basic Examples
Why HCF and LCM Matters
HCF (also GCD) is the largest integer that divides both numbers. LCM is the smallest positive integer that is a multiple of both. Use prime factors or Euclid’s algorithm for HCF, then LCM = ab / HCF.
Applications
Used in school exams, homework, and real-world number problems.
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