# “Least Common Denominator” should be Greatest Common Divisor

Posted on by fred

Category: Uncategorized

Many people use the phrase **least common denominator** to describe something as being base or common. It connotes something that appeals to most people, something that we all value. It is the *intersection* of what we all value, in the set-theory sense. But in arithmetic the LCD is the *union* of the prime factors of the denominators (including the multiplicity of those factors).

Perhaps **greatest common divisor** is a better metaphor for what is typically described as an LCD, the GCD being the intersection of prime factors.