
Octal Number System (Base8)
The octal number system uses EIGHT values to represent numbers. The values are,
0 1 2 3 4 5 6 7
with 0 having the least value and seven having the greatest value. Columns are used in the same way as in the decimal system, in that the left most column is used to represent the greatest value.
As we have seen in the decimal system, the values in the set (0 and 1) repeat, in both the vertical and horizontal directions.
0  7, 10 17, 20  27, 30  37 ......
Example Convert 176 in octal to decimal.
Each column represents a power of 8,
264 becomes .....
4 * 8^{0} = 4
6 * 8^{1} = 48
2 * 8^{2} = 128
adding the results together gives 180 (in decimal)
Octal was used extensively in early mainframe computer systems, but has become less popular in favour of binary and hexadecimal today.


