Octal Number System
The octal number system uses the digits 0,1,2,3,4,5,6 and 7. The base or radix of this system is eight. Each significant position in an octal number has a positional weight. The least significant position has a weight of 80, i.e. 1, the higher significant positions are given weights in the ascending powers of eight, i.e. 81, 82, 83, etc. respectively. The octal equivalent of a decimal number can be obtained by dividing a given decimal by 8 repeatedly, until a quotient of 0 is obtained. The procedure is exactly the same as the double-dabble method.
Octal to Binary Conversion
Conversion from octal to binary and vice versa can be easily carried out. For obtaining the binary equivalent of an octal number, each significant digit in the given number is replaced by its 3-bit binary equivalent. For example.
(376)8 = 3 7 6
011 111 110
Thus, (376)8=(011111110)2. For converting a binary number to an octal, the reverse procedure is used,i.e. starting from the least significant bit, each group of 3 bits is replaced by its decimal equivalent. For example,
(10011010101)2 = 010 011 010 101
2 3 2 5
Thus, (10011010101)2=(2325)8