3 (Three)

3, called saddex in Somali, is a natural number that comes between 2 and 4. It serves two distinct functions: a cardinal function (counting how many things exist) and an ordinal function (indicating position, such as third in a sequence).

The symbol 3 used worldwide today comes from the Hindu-Arabic numeral system. Other numeral systems write it differently; for example, in Roman numerals it is III, and many languages have their own distinct symbols.

Mathematical Properties

3 is a prime number—it can only be divided by 1 and itself. It is the second prime number after 2, and the first odd prime number. It is also a triangular number, since 1+2 = 3.

A well-known test for divisibility by 3 is that if the sum of the digits of a number can be divided by 3, then the number itself can be divided by 3. For example: 123 → 1+2+3 = 6, which is divisible by 3, so 123 is also divisible by 3.

Geometry

Three non-collinear points define a single plane. Three is also the minimum number of sides a closed, rigid shape can have—this is the triangle. For this reason, the triangle has become fundamental to the structure of geometry and engineering drawings, since its shape cannot change if the lengths of its sides are fixed.

General Use

Three appears consistently in cultural, religious, and narrative systems—for example, the beginning, middle, and end of stories. It is also common for prizes to be awarded in three places, such as first, second, and third.