Subtraction of Octal Numbers
The subtraction of octal numbers follows the same rules as the subtraction of numbers in any other
number system. The only variation is in the quantity of the borrow. In the decimal system, you had to
borrow a group of 1010. In the binary system, you borrowed a group of 210. In the octal system you will
borrow a group of 810.
Consider the subtraction of 1 from 10 in decimal, binary, and octal number systems: