title: Computing 2's complement in Excel
body: <p>How can I compute the <strong>2s complement</strong> of a binary number in Excel. Which Excel functions do I need?</p>
  
  <p>For example, if I have the binary sequence <code>11101010</code>, the 2s complement can be obtained as,</p>
  
  <ol>
  <li>Replace all 1's with 0's and 0's with 1's: <code>00010101</code></li>
  <li>add 1 to the result of step 1: <code>00010110</code></li>
  </ol>
  
  <p>An excel implementation of the above is what I need.</p>