Hexadecimal numbers are a mixture of decimal numbers and letters. The decimal number system uses 10 digits, 0 through 9, to represent all numbers. The hexadecimal number system uses 16 symbols, 0 through 9 and the letters A through F, to represent numbers. These letters are used to represent the values 10 through 15, respectively. This makes hexadecimal a convenient way to represent binary data in a compact form, since each hexadecimal digit represents 4 binary digits.