Complement of a Number Octal and Hexadecimal Number Convert Decimal to Binary Subtraction of numbers by using complement Subtraction with r’s Complements The direct method of subtraction taught in elementary schools uses the borrow concept. In this method, we borrow a 1 from a higher significant position when the minuend digit is smaller than the corresponding subtrahend digit. This seems to be easiest when people perform subtraction with paper and pencil. When subtraction is implemented by means of digital components, this method is found to be less efficient than the method that uses complements and addition as stated below. The subtraction of two positive numbers (M - N), both of base r, may be done as follows: 1. Add the minuend M to r’s complement of the subtrahend N. 2. Inspect the result obtained in step 1 for an end carry: a. If the end carry occurs, discard it. b. If an end carry does not occur, take r’s complement of