# Category:Definitions/Specific Numbers

This category contains definitions related to Specific Numbers.
Related results can be found in Category:Specific Numbers.

There are five main classes of number:

$(1): \quad$ The natural numbers: $\N = \set {0, 1, 2, 3, \ldots}$
$(2): \quad$ The integers: $\Z = \set {\ldots, -3, -2, -1, 0, 1, 2, 3, \ldots}$
$(3): \quad$ The rational numbers: $\Q = \set {p / q: p, q \in \Z, q \ne 0}$
$(4): \quad$ The real numbers: $\R = \set {x: x = \sequence {s_n} }$ where $\sequence {s_n}$ is a Cauchy sequence in $\Q$
$(5): \quad$ The complex numbers: $\C = \set {a + i b: a, b \in \R, i^2 = -1}$

## Subcategories

This category has the following 15 subcategories, out of 15 total.

## Pages in category "Definitions/Specific Numbers"

The following 77 pages are in this category, out of 77 total.