A rational number is sometimes referred to as a fraction.

A rational number or fraction can be used to indicate equal parts of a whole.
eg. We may refer to a half of pizza, or half of an orange.

A proper fraction consists of 3 parts :
(1) A Numerator - this is the top part of the fraction which tells us how much parts of the   whole is being considered.
(2) A Fraction Bar.

(3) A Denominator - this is the bottom part of the fraction which tells us how many equal parts the whole was divided into.

An improper fraction is a fraction where the numerator is greater than or equal to the denominator.
An improper fraction is equal to or greater than one, while a proper fraction is always less than one.

Note: The denominator of a fraction cannot be zero (remember a number cannot be divided by zero ).
 

Equivalent Fractions   - are equal fractions.
Two fractions are equivalent if they represent the same amount.
Although the numbers may look different, calculations will show that equivalent fractions are equal, or are the same fractions.
If a pizza is divided into 8 equal slices, and you get 4 of the 8 slices, then it is the same as receiving half.
This just means that the same pizza was divided into 2, and you got 1 of the 2 portions which is half.
 

You can create an equivalent fraction, by multiplying the numerator and the denominator of a fraction by the same number, or dividing the numerator and the denominator of a fraction by the same factor. (note: the fundamental property of fractions - next)

We can use this property of fractions to :
(1) Determine Equivalent Fractions
(2) Simplify fractions
(3) Express fractions in higher terms

The Reciprocal of a fraction is a fraction with the numerator and denominator inverted.

The reciprocal of a fraction multiplied by the fraction equals 1.
Any number multiplied by it's reciprocal give a value of 1.