将以下句子翻译成汉语:1、Numbers consist of several symbols in the number system.2、Number systems can be approximately classified into two systems: positional number system and non-positional number system.3、In a positional number system, the position of a symbol in the number presentation has its own specific value, which is called a place value.4、In a non-positional number system, every symbol have specific values, but the position of a symbol in the number presentation has no relationship with its value.5、In a decimal system, the base equals 10 and there are 10 symbols. The symbols are regarded as decimal digits.6、In a binary system, the base equals 2 and there are just 2 symbols. The symbols are regarded as binary digits.7、In a hexadecimal system, the base equals 16 and there are 16 symbols. The symbols are regarded as hexadecimal digits.8、In an octal system, the base equals 8 and there are 8 symbols. The symbols are regarded as octal digits.9、In the process of converting a number in any number system to a decimal number, we multiply each digit with its corresponding place value, and add them together to obtain the result.10、When we convert a real, we need two steps: one is converting the integral part of the real; another is converting the fraction part of the real. The former uses repetitive division, the latter uses repetitive multiplication.11、Because four digits in a binary system can be represented by one digit in a hexadecimal system, we can use this relationship to solve the problems of conversion between a binary system and a hexadecimal system.12、Similar to the conversion between a binary system and a hexadecimal system, as three digits in a binary system can be represented by one digit in an octal system, we can make full use of this relationship to solve the problems of conversion between a binary system and an octal system.13、In the process of conversion between an octal system and a hexadecimal system, we can make full use of the binary-octal relationship and binary–hexadecimal relationship to realize our goal.