Rational Numbers
Any number that can be written as a fraction with integers is called a rational number .
For example, are rational numbers.
(Note that there is more than one way to write the same rational number as a ratio of integers. For example, and represent the same rational number.)
All integers are rational numbers.
The number is a rational number because it can be rewritten as .
The number is a rational number because it can be rewritten as .
All mixed numbers are rational numbers.
is a rational number because it can be re-written as .
All decimals which either terminate or have a repeating pattern after some point are also rational numbers.
The number is a rational number because it can be re-written as .
The number is a rational number because it can be re-written as .
Some numbers can't be rewritten as a fraction with integers, and so they are not rational numbers. Some examples are and the square root of any prime number. These are called irrational numbers.