Lowest common denominator
In mathematics, the lowest common denominator or least common denominator (abbreviated LCD) is the least common multiple of the denominators of a set of fractions. For instance, the LCD of {1/2, 1/4} is 4, while the LCD of {1/2, 1/3} is 6.
By using this as a denominator, it enables addition, subtraction or comparision of fractions:
- 1/2 + 1/4 = 2/4 + 1/4 = 3/4
- 1/2 - 1/3 = 3/6 - 2/6 = 1/6
- 1/3 < 2/5 since 5/15 < 6/15
In non-mathematical use, the term is commonly used to refer to the target audience of mass media. It tends to be overused in this regard, or at least considered synonymous with "dumbest people". Action movies and most television programming are often considered to be targeted at the lowest common denominator of the population. It is also used to describe negotiations and agreements which only cover the points where everybody's previous positions coincide. Highest common factor would be a more accurate description, but would not have the same negative sound.
