1. Octal
• Eight digits: 0, 1, 2, 3, 4, 5, 6, 7
• Octal is base 8
• Positional numeral system
– The position of the symbol specifies the multiplier (as a power of 8)
• Counting
– Go through all the symbols in one position, increment the symbol in
the next highest position, repeat.

2. Octal
Octal Dec
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
Octal Dec
10 8
11 9
12 10
13 11
14 12
15 13
16 14
17 15
Octal Dec
20 16
21 17
22 18
23 19
24 20
25 21
26 22
27 23

3. Octal
• Number: 15678
Position 3 2 1 0
Multiplier 83 = 512 82 = 64 81 = 8 80 = 1

183
  5 82
  6 81
  7 80
 
512 320 48 7
 887