• Has 8 digits: 0, 1, 2, 3, 4, 5, 6, 7
• Value of digits increase by 8 for each position

   Example:

      153(8) = 1 x 82 + 5 x 81 + 3 x 80
	     = 64 + 40 + 3 = 107

• Divide the value repeated by 8
• Collect the remainders in the reverse order

(The procedure is exactly the same as the one to find the representation for a value in the binary number system, except you need to divide by 8 instead of 2)

 Example:

     value = 23

 Find the representation in the octal number system:

        23
    8 ------ 7
	 2
    8 ------ 2
	 0

    representation is ----> 27(8)
 

• Convert each octal digit to 3 binary digits using:

        Octal digit       Binary digits
        -----------       -------------
              0      -->         000
              1      -->         001
              2      -->         010
              3      -->         011
              4      -->         100
              5      -->         101
              6      -->         110
              7      -->         111
  
     Example:
  
        153(8) = 01101011(2)
  

• Convert (starting from the right) each group of 3 binary digits into one octal digit using:

        Binary digits     Octal digit
        -------------     -----------
            000       -->      0
            001       -->      1
            010       -->      2
            011       -->      3
            100       -->      4
            101       -->      5
            110       -->      6
            111       -->      7
  
     Example:
  
        11111101(2) = 375(8)