One, number
Is used as a count or marker as a measure of the abstract, is relatively simple symbols homogenous or recording format of the same level of the properties of things (or metric). In daily life, the number typically found on the tag (e.g., roads, telephone and house number), index (sequence number) and code. In mathematics, extends to the definition of the abstract concepts such as containing fractions, negative, irrational number, and plural beyond the like.
Second, the number system
Before speaking band, first understand the number system. What then is the number system, the number of system, also known as the "counter" system, with symbols and uniform set of rules to represent the fixed value of the method. In our daily lives, with a number of statistics to an object or objects of "quantity", usually behind the number will follow the "quantity" of the unit, that is to say the "quantity" nature of what we want to express, and the number is only the "quantity" in a particular symbol system alleged that a quantity can be represented in many kinds of symbolic systems, the symbol just allegations. The number of points is formed with the non-binary notation the binary notation. Non-binary notation (such as rope original notation, commonly used when the tellers "n" word count method) regardless of the magnitude of digital values represented by its position in the number, and here we do not make too much introduction.
Third, hex
The concept of "number system" above, we can draw band is binary notation, it is a way of expressing the number of system, a method for counting the carry bit arbitrarily defined. The numerical size of the digital binary notation represented is related to its location in the numbers. It contains binary elements:
- Bit
is the location, the location of a binary digital in which the number of bits that can be used to measure the length of the number. Generally from left to right, the left is high, the right is low, we can in order to facilitate the expression we can give the place a name, such as decimal number, ten, hundred, thousand, million - Digital
i.e. the number of symbols of the expression, the number of system symbols representing different numbers of basic numerical values. For example, the decimal 0,1,2,3,4,5,6,7,8,9. - Base
number of digital. For example, the base binary number is 2. Decimal radix is 10. Base hexadecimal number is 16. - Bit right
position i.e. the position, that is, the right weight, each digital unit value corresponding to the position right as bits, i.e. "1" values at different positions on different represented in the hexadecimal. For example decimal digits to the right of the second bit 10, bit position 3 for the right 100; and the second binary bit weights of 2 bits, 3 bits of the right to 4 ,. So we can conclude that the corresponding digital value is equal to a certain position on the digital rights multiplied by bit. It can be interpreted this way: the right is a digital bit at a location on the stepper, stepping sample sizes in different locations, small high large low.
By the above information, we can draw band definition: that is, with a particular symbol system in a fixed number of symbol combinations different symbols are placed at different positions into variable length symbols to represent a combination of a number, in calculations, when the value of the base to meet on a bit, go out into a high unit value "1", this rule is binary . Typically, the base is X, we called X-band, somewhere, every X carry. For example: decimal, Arabic notation system used in its sign of 0,1,2,3,4,5,6,7,8,9 these 10 symbols, the base is 10, then on a bit foot 10 will carry, for example, the result 9 + 1 becomes two-digit 10.