Key learning points

1. Both the LCM and HCF can be found by comparing the prime factorisation of the numbers.
2. A Venn diagram can be a helpful representation.
3. This representation can be extended to consider three numbers.
4. The context of the question can make it clear whether the LCM or HCF would be the most useful.

Keywords

• HCF - HCF is an abbreviation for highest common factor.

• LCM - LCM is an abbreviation for lowest common multiple.

• Prime factorisation - Prime factorisation is a method to find the prime factors of a given integer.

• Product of primes - Expressing a number as a product of primes means writing it uniquely as a product of its factors that are prime numbers.

Common misconception