Number

One Number (of old-French cifre; mlat. cifra; arab. sifr; aind. safira =empty its) is in Numeral. The term originally designates those Zero.

A number is in written Indication, for the representation of Numbers one uses. A number becomes today by combination one or several numbers in the framework one Notational system represented.

In different cultures and give there were different Number writings, today are those Arabic numerals (in regionally different modifications) prevailing.

The number of different numbers becomes by the used Number system specified:

• In the most common Decimal system there are ten numbers, indeed the numbers 0 to 9, from those each number is compound.
• In the electronic data processing one uses, predominantly internally, that Binary system with the two numbers 0 and 1. It becomes a binary (= bivalent) Condition used, each individual place of a number places a in such a way specified Bit .
• That Hexadecimal number system additionally 0 to 9 also still the letters A to F use to the numbers (often also small written). This alphanumeric mixing system with its sixteen numbers is, since center of the 1950er years, those Standard representation for hexadecimal numbers. Since this number system is not unambiguous however in program codes ("af123" can describe the number of af123 or a variable with name af123), needs it Prae or Suffixe always clarifying (z.B. Prefix 0x). For some years a suggestion exists, hexadecimal numbers generally with new, unambiguous, so-called omni litteralen (Dh. only letters - to represent) numbers. (C.f. Hexadecimal time). The hexadecimal number system is gladly used in computer science, because it illustrates for each number accurately 4 bits and thus is related to the binary system.
• With BCDNumbers has one a system of the computer engineering, with 16-wertigen groups of only 10 values actually uses. It concerns thus a decimal system, however to the binary system by use of hexadecimal well-known place arrangement one adapted ago.
• In the computer engineering still that is as Exot Octal system, which on the basis of the numbers 0 to 7 is formed.
• Those Indian South America used number systems for the basis 4, 8 or 16, since they counted on hands and feet, however the thumbs thereby not to include wanted.

The terms Number and Number in the German language are falsely frequently synonymously used. For example in the term Dark number, those actually a number is, thus mathematically correctly actually are called dark number would have. The correct use: Those Number 23 consists of that Numbers 2 and 3 and not from that Numbers 2 and 3. This is comparably to the formation rule that Writing: Words consist of Letter, also Type characters are called.

In number systems, none Notational systems are - approximately with that Roman numbers - does not speak one generally of "numbers".

Besides one means also Number a subsection in one, marked by a number Law- and Contract text.