title: Why is modulus operator slow?
body: <p>Paraphrasing from in "Programming Pearls" book (about c language on older machines, since book is from the late 90's):</p>
  
  <p>Integer arithmetic operations (<code>+</code>, <code>-</code>, <code>*</code>) can take around 10 nano seconds whereas the <code>%</code> operator takes up to 100 nano seconds.</p>
  
  <ul>
  <li>Why there is that much difference?</li>
  <li>How does a modulus operator work internally?</li>
  <li>Is it same as division (<code>/</code>) in terms of time?</li>
  </ul>