Example Find the HCF and LCM of 24 and 180. Start by writing 24 and 180 as the product of their prime factors. The product of prime factors for 24 are: \ (2 \times 2 \times 2 \times 3\) ...

To find the HCF, find any prime factors that are in common between the lists. Each list contains two 2s and one 3, so use these for the HCF. HCF = \ (2 \times 2 \times 3 = 12\) ...