6

The number six is special and important. It comes after five and before seven. In math, six is a composite number, meaning it can be divided into smaller whole numbers besides just one and itself.

One cool fact about six is that it is the smallest perfect number. A perfect number equals the sum of its parts. For six, the parts are one, two, and three. When you add them (1 + 2 + 3), you get six.

Numbers like six help us count, measure, and understand the world. We use them in many daily activities, like telling time and playing simple games.

In mathematics

A six-sided shape is called a hexagon. Hexagons are special because they can cover a flat surface without leaving gaps. A hexagon has 6 sides and 6 corners.

The number 6 is special in math. It is the smallest number that can be divided evenly by smaller numbers besides just 1 and itself. This makes it a unique and important number in many math ideas.

Greek and Latin word parts

Hexa

Hexa is the Greek word for "six". This prefix is used in many words:

• "Hexadecimal" mixes hexa- with decimal to describe a number base of 16.
• A hexagon is a polygon with six sides.
  • L'Hexagone is a French nickname for the main part of Metropolitan France because it looks like a regular hexagon.
• A hexahedron is a polyhedron with six faces, and a cube is a special example.
• Hexameter is a poetic style with six beats in each line.
• A "hex nut" is a nut with six sides, and a hex bolt has a six-sided head.
• The prefix "hexa-" is used in the systematic name of many chemical compounds, like hexane, which contains 6 carbon atoms (C₆H₁₄).

The prefix sex-

Sex- is a Latin prefix meaning "six". It appears in these words:

• Senary is an adjective meaning "sixth".
• People with sexdactyly have six fingers on each hand.
• A sextant is named for forming one-sixth of a whole circle.
• A group of six musicians is called a sextet.
• Six babies born at the same time are sextuplets.
• Sexy prime pairs are pairs of prime numbers that differ by six.

The SI prefix for 1000⁶ is exa- (E), and for its reciprocal atto- (a).

Evolution of the Hindu-Arabic digit

The modern digit 6 has a simpler history than many other digits. It began with the Brahmi numerals from India, around 250 BCE in the Edicts of Ashoka. It was first written like a cursive lowercase "e" turned 90 degrees. Over time, its top became more curved, and the bottom straighter. The Arabs removed the lower part of the stroke. This led to the 6 we use today in Europe, with only a short time when it looked more like a large letter "G".

On seven-segment displays in calculators and watches, the number 6 is shown using six segments. Some older calculators used only five segments by skipping the top horizontal line, but this style was not popular. In most modern typefaces, especially those with special number styles called text figures, the digit 6 often rises above the normal line, similar to some letters.

The digit 6 can look like an upside-down 9. To prevent confusion when something is turned over, people often underline the 6 to make it clear.

Chemistry

Snowflakes have a six-sided shape because of how ice forms in a hexagonal crystal structure. This makes the beautiful, symmetrical patterns we see in snowflakes.

Anthropology

In some traditions, a coffin is buried six feet under the ground. This is why the phrase "six feet under" means that someone has passed away. In Chinese culture, the number six is considered lucky. The word "six" is also sometimes used to refer to the British Secret Intelligence Service, known as MI6.