Draft:Outline of numbers

The following outline is provided as an overview of and topical guide to numbers:

A number is a mathematical object used to count, measure, and label. The most basic examples are the natural numbers: 1, 2, 3, 4, 5, and so forth. Individual numbers can be represented in language with number words or by dedicated symbols called numerals; for example, "five" is a number word and "5" is the corresponding numeral. As only a limited list of symbols can be memorized, a numeral system is used to represent any number in an organized way. The most common representation is the Hindu–Arabic numeral system, which can display any non-negative integer using a combination of ten symbols, called numerical digits. Numerals can be used for counting (as with cardinal number of a collection or set), labels (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, a numeral is not clearly distinguished from the number that it represents.

What type of things are numbers?

Numbers can be described as all of the following:

• Abstract concepts
  • Symbols
    • Fundamental elements of mathematics
      • Quantitative descriptors

Types of numbers

Main article: List of types of numbers

• Natural numbers
• Integers
• Irrational numbers
• Real numbers
• Prime numbers
• Complex numbers
  • Algebraic numbers
    • Rational numbers

Hypercomplex numbers

• Hypercomplex number
• Bicomplex number
• Biquaternion
• Bioctonion
• Dual numbers
• Dual complex numbers
• Dual quaternion
• Quaternions
• Octonions
• Sedenions
• Split-biquaternion
• Split-complex numbers
• Split-quaternion
• Split-octonion

Other types

• Transfinite numbers
• p-adic numbers

History of numbers

History of numbers

Applications of numbers

• Accounting

• Calculation

• Counting

• Mathematics

General numbers concepts

• Numeral system