6

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

One of the most interesting facts about six is that it is the smallest perfect number. A perfect number is a number that equals the sum of its parts. For six, the parts are one, two, and three, and when you add them together (1 + 2 + 3), you get six.

Numbers like six help us count, measure, and understand the world around us. They are used in many everyday activities, from telling time to playing simple games.

In mathematics

A six-sided shape is called a hexagon. Hexagons are special because they are one of the simple shapes that can cover a flat surface without 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, called "sexy" because sex is the Latin word for 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 compared to other digits. It started with the Brahmi numerals from India, appearing around 250 BCE in the Edicts of Ashoka. It was originally written like a cursive lowercase "e" turned 90 degrees. Over time, its top part became more curved, and the bottom part straighter. The Arabs removed the lower part of the stroke. From there, it evolved into the 6 we use today in Europe, with only a brief period when it looked more like a large letter "G".

On seven-segment displays used in calculators and watches, the number 6 is shown using six segments. Some older calculators used only five segments by leaving out the top horizontal line, but this style did not become 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 certain letters.

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

Chemistry

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

Anthropology

In some traditions, a coffin is buried six feet under the ground, which 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 as a casual way to refer to the British Secret Intelligence Service, known as MI6.