Octal to Binary Number System

Octal number has base 8    from digit 0 – 7  written as  (324)₈

Binary    Decimal

1. 000          0
2. 001          1
3. 010          2
4. 011          3
5. 100          4
6. 101          5
7. 110          6
8. 111          7

Convert Octal to Binary

1. (116)₈    ——-    (  001  001  110  ) ₂ 
   SO BINARY number for octal 116 is 1001110  just by putting 3 bit value for each digit in octal.
2. (574.321)₈    ——-    ( 101 111 100.011 010 001 ) ₂ 
   SO BINARY number for octal 574.321 is101 111 100.011 010 001  just by putting 3 bit value for each digit in octal.

Convert Octal to Decimal

1. (116)₈ =  1×8² +   1×8¹ +6×8⁰   = 64+8+6  = (78)₁₀  

Convert Decimal to octal

1. (70)₁₀    =   8  | 70 |  6
   8  |   8 |  0
   1        there for the octal number of 70 base 10  is 106 base 8