Octal (Positional systems), numerals
The octal numeral system is the base-8 number system, and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping consecutive digits into groups of three (starting from the right). For example, the binary representation for decimal 74 is 1001010, which groups into 1 001 010 — so the octal representation is 112. Octal is sometimes used in computing instead of hexadecimal.