Octal and Hexadecimal Number Systems. OCTAL or BASE-8 numbers uses eight symbols: 0, 1, 2, 3, 4, 5, 6, and 7 (count them!) and position plays. a major role in expressing their meaning. For example 53,702. 8. means. 45 x 8 3+ 3 x 8 + 7 x 82 + 0 x 81 + 2 x 80.