The number system which uses eight symbols or digits is referred to as octal number system.
This number system uses only the digits ranging from zero( 0 ) to seven( 7 ) for counting as well as performing various arithmetic operations.
Even though the name of the number system is octal number system, the digit 8 is not used in this number system.
The radix or base in octal number system is 8 since it involves eight ( 8 ) symbols.
In this number system the weights are all powers of 8.
The generic format for representing any number in binary number system is as show below
84 83 82 81 80 8-1 8-2 8-3 8-4 ← Weights
MSD Octal point LSD
MSD i the most significant digit
LSD is the least significant digit
S1 ,S2 ,S3 ....Sn are values assigned.
Representing larger numbers in binary number system was a difficult task and hence the other two number systems namely octal number system and hexadecimal number system were introduced.