rational numbers
In decimal form, rational numbers are either terminating or repeating decimals. [1]
The same is true for any other integral base above one, and is also true when rational numbers are considered to be p-adic numbers rather than real numbers. [2]
Rational numbers are simply numbers that can be written as fractions or ratios (this tells you where the term rational comes from). [3]
This is the archetypical field of characteristic zero, and is the field of fractions for the ring of integers. [1]
The rationals are a densely ordered set: between any two rationals, there sits another one, in fact infinitely many other ones. [2]
This includes integers, terminating decimals, and repeating decimals as well as fractions. [...] Whole Numbers: Zero and the positive integers are the whole numbers. [3]
In abstract algebra, the rational numbers form a field. [4]
Irrational Numbers: Any real number that cannot be written in fraction form is an irrational number. [3]
In mathematics, a name can be used with a very precise meaning that may have little to do with the meaning of the English word. [5]
More formally each rational number corresponds to an equivalence class. [...] In mathematics, a rational number is any number that can be expressed as the quotient a/b of two integers, with the denominator b not equal to zero. [1]
In mathematics, a rational number is a number that can be expressed as a ratio of two integers. [2]
A rational number is any number that can be written as a ratio of two integers (hence the name!). [5]
By virtue of their order, the rationals carry an order topology. [2]
Sources:
[1] rational number: Definition from Answers.com
[2] Rational number - encyclopedia article - Citizendium
[3] MathSteps: Grade 7: Rationals: What Is It?
[4] Rational number - Wikipedia, the free encyclopedia
[5] Math Forum: Ask Dr. Math FAQ: Integers, Rational Numbers, Irrational …