title: Twos Complement Addition. -48 - 23. Is it necessary to use 8-bit representation?
body: <p>The approach I am using to solve this is that I first write both numbers in 2s Complement form.
  For this I first convert 48 and 23 to binary, then ones complement the binary representation and add 1.</p>
  <p>48 = (0110000), 23 = (0010111) {In Binary Signed Representation)</p>
  <p>Now their twos complement are -48 = (1010000), -23 = (1101001).</p>
  <p>Now I just add them:</p>
  <p><a href="https://i.stack.imgur.com/COGAA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/COGAA.png" alt="enter image description here" /></a></p>
  <p>Now in my textbook it's written that final carry 1 should be discarded. If I discard that I get wrong answer. If I use 8-bit representation instead of 7 bits I get correct answer.</p>
  <p>So my question is Why isn't 7-bit representation giving correct answer? Is it necessary to use some 2^n representation?</p>