Having presented binary representations for unsigned and signed integers, we’re ready to use them in arithmetic operations. Fortunately, due to their encoding, it does not matter to the arithmetic procedures whether we choose to interpret the operands or result as signed or unsigned. This observation is great news for hardware designers, since it allows them to build one set of hardware components that can be shared for both unsigned and signed operations. The hardware chapter describes the circuitry for performing arithmetic in more detail.
Luckily, the same pencil-and-paper algorithms you learned in grade school for performing arithmetic on decimal numbers also work for binary numbers. Though the hardware might not compute them in exactly the same way, you should at least be able to make sense of the calculations.