A

**number** is a mathematical object used to quantify (count and measure) and to represent quantity, in several forms, of which the most primitive, primary and simplest one is the symbolic signification of a particular, invariable, constant quantity. A notational symbol that represents a

**number** is called a numeral but in common use, the word number can mean the abstract object, the symbol, or the word for the

**number**. In addition to their use in counting and measuring, numerals are often used for labels (telephone

? numbers), for ordering (serial numbers), and for codes (e.g., ISBNs). In

mathematics, the definition of

**number** has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Certain procedures that take one or more numbers as input and produce a number as output are called numerical operations. Unary operations take a single input number and produce a single output number. For example, the successor operation adds one to an integer

?, thus the successor of 4 is 5. More common are binary operations, which take two input numbers and produce a single output number. Examples of binary operations include

addition,

subtraction,

multiplication,

division, and exponentiation

?. The study of numerical operations is called

arithmetic. (wikipedia)

The symbols for the digits 1 - 9 were derived from the ancient astrological symbols for the planets.

**Where did numbers come from?**
See Also

**12.21 - Fibonacci Whole Numbers v Irrational Decimal near Equivalents**
**Addition**
**Arithmetic**
**atomic number**
**Chord**
**Delta**
**Division**
**Figure 3.00 - Infinite Number of Atomoles or Alphanon filling all Space**
**Geometry**
**Indig Numbers**
**Interval**
**law of multiple proportions**
**law of constant composition**
**Law of Definite Proportions**
**mass number**
**Multiplication**
**Music**
**Number**
**Oxidation Number**
**proton number**
**Proportion**
**Propositions of Geometry**
**Quantum Arithmetic**
**Ratio**
**Stoichiometry**
**Subtraction**
**wave number**