| |
| | Number - Wikipedia, the free encyclopedia |
 | | The arithmetical operations of numbers, such as addition, subtraction, multiplication and division, are generalized in the branch of mathematics called abstract algebra, the study of abstract number systems such as groups, rings and fields. |
 | | The existence of complex numbers was not completely accepted until the geometrical interpretation had been described by Caspar Wessel in 1799; it was rediscovered several years later and popularized by Carl Friedrich Gauss, and as a result the theory of complex numbers received a notable expansion. |
 | | The first known use of numbers dates back to around 30000 BC when tally marks were used by stone age peoples. |
| en.wikipedia.org /wiki/Number (3652 words) |
|