Base 8 (or
octal) is a number system with only the
digits from 0 to 7. It is (or used to be) useful in
computing/
digital systems, because each digit is represented by exactly three
bits, or three digits of
base 2.
Binary | Octal | Decimal
------------------------
0000 | 0 | 0
0001 | 1 | 1
0010 | 2 | 2
0011 | 3 | 3
0100 | 4 | 4
0101 | 5 | 5
0110 | 6 | 6
0111 | 7 | 7
1000 | 10 | 8
1001 | 11 | 9
1010 | 12 | 10
1011 | 13 | 11
1100 | 14 | 12
1101 | 15 | 13
1110 | 16 | 14
1111 | 17 | 15
Thus, it is easy to convert numbers between binary and octal, simply convert three and three bits. Example: 1000110110(2) = 1 ; 000 ; 110 ; 110(2) = 1066(8)
See also hexadecimal for a similar explanation of base 16.
"Base 8 is just like base 10, really. If you're missing two fingers!"
-
Tom Lehrer