title: how to validate the number of decimal for a numeric value?
body: <p>I have my validation in the modle like follows:</p>
  
  <pre><code>validates_numericality_of :shoe_size, :message=&gt;'Please input a number'
  </code></pre>
  
  <p>But this is not enough because user can input some value like "42.22222222121212121212..." which is not expected. So, how to validate the input to have only <strong>two decimals</strong> like 42.22</p>