Q. What do you mean by Number Systems?

The Digital circuits are inherently binary in nature, but numerous types of representations of numerical data are in use.

The representation of an unsigned integer can be done in octal, binary, decimal or hexadecimal. For the display purposes, each decimal digit is often represented by a four-bit binary number in a system called binary coded decimal (BCD). The Conversions between these representations can be handled in a routine manner.

The representation of signed numbers presents additional problems and those problems are addressed in various ways. Some of the codes used are "offset binary", "sign magnitude", "2's complement", "excess-3", "4221", and "Gray". A table able to show the display of four-bit integers.