The lowest common multiple (LCM) of two numbers or more numbers is the smallest ‘integer’ that is divisible by both or all of them.
-
Listing Multiples:
- List the multiples of each number until at least one of the multiples appears on all lists.
- Find the smallest number that is on all of the lists. This number is the LCM.
- Example: For LCM(6, 7, 21), the multiples are:
- Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60
- Multiples of 7: 7, 14, 21, 28, 35, 42, 56, 63
- Multiples of 21: 21, 42, 63
- The smallest number on all lists is 42, so LCM(6, 7, 21) = 42.