Lowest common denominator

The lowest common denominator (also least common denominator and LCD) is the least common multiple of the denominators (bottom parts) of a group of fractions. It makes it easier to add, subtract, and compare fractions.

The LCD of  and  is 6. This is because  and  equal  and . 6 is the smallest number that can be at the bottom of both of those fractions.

The same thing also works with variables:



Category:Fractions (mathematics)