- Example:
- Find the least common denominator (LCD) for 5/18 and 6/27

- Solution:
- The denominator of the first fraction is 18
- The denominator of the second fraction is 27, then
- multiples of 18, 1 × 18 = 18, 2 × 18 = 36, 3 × 18 = 54, 4 × 18 = 72
- multiples of 27, 1 × 27 = 27, 2 × 27 = 54
- Note: 27 × 2 = 54 and 18 × 3 = 54
- Therefore, 54 is the least common denominator (LCD) for fractions 5/18 and 6/27

Using the least common denominator when perform addition or subtraction of fractions with different denominators.