Denominator and Numerator Common Denominator

Simplifying, or Reducing the Fraction
Numerator / Denominator
We call the top number the Numerator, it is the number of parts we have.
We call the bottom number the Denominator, it is the number of parts the whole is divided into.
Numerator/Denominator
You just have to remember those names! (If you forget just think "Down"-ominator)

The definition of a denominator means something that is shared, or is the standard, or the number below the line in a fraction.

An example of a denominator is the red hair color shared by all members of a family.

An example of a denominator is a common level of writing expected in a composition class.

An example of a denominator is the "2" in the fraction "½."

Adding Fractions

It is easy to add fractions with the same denominator (same bottom number):

^1/4	+	^1/4	=	^2/4	=	^1/2
(One-Quarter)		(One-Quarter)		(Two-Quarters)		(One-Half)
	+		=		=

One-quarter plus one-quarter equals two-quarters, equals one-half
Another example:

^5/8	+	^1/8	=	^6/8	=	^3/4
	+		=		=

Five-eighths plus one-eighth equals six-eighths, equals three-quarters
Adding Fractions with Different Denominators
But what about when the denominators (the bottom numbers) are not the same?

^3/8	+	^1/4	=	?
	+		=

Three-eighths plus one-quarter equals ... what?
We must somehow make the denominators the same.
In this case it is easy, because we know that ¹/₄ is the same as ²/₈ :

^3/8	+	^2/8	=	^5/8
	+		=

Three-eighths plus two-eighths equals five-eighths
There are two popular methods to make the denominators the same:

• 
  Least Common Denominator or
  
• 
  Common Denominator
  

(They both work nicely, use the one you prefer.)

Definition of Denominator

When an integer is expressed as a fraction, then there appear two numbers separated by a horizontal line. The denominator is the number that appears at the bottom of the horizontal line, whereas the number above the line is the numerator. It is not necessary that only numerical values are expressed in the numerator and denominator form, instead, the variables are also expressed in the same form such as x/y, p/q, m/n, etc., where y, q, and n are the denominators respectively.
A fraction consists of two numbers. Symbolically it is represented by two numbers separated by a horizontal line (–) or slash line (/). The number above the line is the numerator, and the number below the line is the denominator. The term denominator is widely used in ratio and proportion concept.

In the above figure, 4, 2, and 4 are the denominators of 1/4, 1/2, and 3/4 respectively.

The denominator value should not be zero. Because, if the value of the denominator is zero, the fraction value should be undefined. For example, 5/0 is a fraction, which is undefined as the denominator value is zero.