Octal is a base 8 numbering system, in which each digit of an octal number has 8 possible values, 0-7. Octal is useful in computers when representing values that fill three bit multiples. For example, Unix file permissions use octal numbering, because the actual binary data that represents file permissions are twelve bits long.
You can use the provided table to convert each octal digit to its three digit binary equivalent.
723518 to binary:
723518 = 1110100111010012