Circa 300 BC, as part of theBrahmi numerals, various Indians wrote a digit 9 similar in shape to the modern closingquestion mark without the bottom dot. The Kshatrapa, Andhra and Gupta started curving the bottom vertical line coming up with a3-look-alike.[1] How the numbers got to their Gupta form is open to considerable debate. The Nagari continued the bottom stroke to make a circle and enclose the 3-look-alike, in much the same way that the sign @ encircles a lowercasea. As time went on, the enclosing circle became bigger and its line continued beyond the circle downwards, as the 3-look-alike became smaller. Soon, all that was left of the 3-look-alike was a squiggle. The Arabs simply connected that squiggle to the downward stroke at the middle and subsequent European change was purely cosmetic.
While the shape of the glyph for the digit 9 has anascender in most moderntypefaces, in typefaces withtext figures the character usually has adescender, as, for example, in.
The form of the number nine (9) could possibly derived from the Arabic letterwaw, in which its isolated form (و) resembles the number 9.
The modern digit resembles an inverted6. To disambiguate the two on objects and labels that can be inverted, they are often underlined. It is sometimes handwritten with two strokes and a straight stem, resembling a raised lower-case letterq, which distinguishes it from the 6. Similarly, inseven-segment display, the number 9 can be constructed either with a hook at the end of its stem or without one. MostLCD calculators use the former, but someVFD models use the latter.
Casting out nines is a quick way of testing the calculations of sums, differences, products, andquotients ofintegers indecimal, a method known as long ago as the 12th century.[3]
9 is the only square number that is the sum of two consecutive, positive cubes:[4]
Non-intersectingchords between four points on a circle
9 is the sum of thecubes of the first two non-zero positive integers which makes it the first cube-sum number greater thanone.[6] A number that is 4 or 5modulo 9 cannot be represented as thesum of three cubes.[7]
Nine is strongly associated with theChinese dragon, a symbol of magic and power. There are nine forms of the dragon, it is described in terms of nine attributes, and it has nine children. It has 117 scales – 81yang (masculine, heavenly) and 36yin (feminine, earthly). All three numbers are multiples of 9 (9 × 13 = 117,9 × 9 = 81,9 × 4 = 36).[17]
The word "K-9" pronounces the same ascanine and is used in many US police departments to denote thepolice dog unit. Despite not sounding like the translation of the wordcanine in other languages, many police and military units around the world use the same designation.
Someone dressed "to the nines" is dressed up as much as they can be.
In North Americanurban culture, "nine" is a slang word for a9mmpistol orhomicide, the latter from the Illinois Criminal Code for homicide.
The number 9 is revered in Hinduism and considered a complete, perfected and divine number because it represents the end of a cycle in thedecimal system, which originated from the Indian subcontinent as early as3000 BC.
Nine is the number associated with Satan inLaVeyan Satanism.Anton LaVey wrote in The Satanic Rituals that this is because nine is the number of theego since it "always returns to itself" even after being multiplied by any number.
