Octal

Octal is a numeral system for representing a numeric value as base 8. Generally, an octal digit is represented as "0" to "7" with the same value as for decimal but with each place a power of 8. For example:

${\displaystyle \mathbf {112} _{8}=\mathbf {1} \times 8^{2}+\mathbf {1} \times 8^{1}+\mathbf {2} \times 8^{0}}$

In decimal, each place is a power of ten. For example:

${\displaystyle \mathbf {74} _{10}=\mathbf {7} \times 10^{1}+\mathbf {4} \times 10^{0}}$

An octal digit can represent the value of a 3-digit binary number (starting from the right). For example, the binary representation for decimal 74 is 1001010. Two zeroes can be added at the left: (00)1 001 010, corresponding to the octal digits 1 1 2, yielding the octal representation 112.