title: Abbreviating numbers with Ruby?
body: <p>How would I abbreviate numbers using Ruby?</p>
  
  <pre><code>1,518,181 to 1.5M
  481,191 to 481k
  95,562 to 95k
  </code></pre>
  
  <p>For this particular project I happen to be using Rails, so if there's some obscure helper method I'm not aware of, it'd be fine to use that here.</p>