The highest common factor is 4. The lowest common multiple (LCM) is found by listing multiples of each number and circling any common multiples. The lowest one is the lowest common multiple.

The only common prime factor is 3, so 3 is the HCF of 120 and 63. Find the Lowest Common Multiple of 120 and 63. 120 = 2³ × 3 × 5 and 63 = 3² × 7. The only prime factor common to each product ...