title: How to specify decimal precision in a simple_form number field (Rails)
body: <p>So I have a decimal field with precision 2 in the database, meant to be used for currency. It works fine unless the last decimal place ends in 0, ie. 799.90. It will instead strip it to 799.9 when it's displayed in the field. I know about <code>number_with_precision</code>, but I haven't been able to use that helper method with the simple_form number field since it only takes a symbol and html options as arguments.</p>
  
  <p>I figured then that I would need to create a custom input to extend simple_form's default number_field, but the syntax doesn't seem to be well documented, so I haven't been able to figure out how I might call <code>number_with_precision</code> in the definition of this custom input.</p>
  
  <p>I essentially want to do what the OP of this question <a href="https://stackoverflow.com/q/8857770/1459498">Formtastic number field with decimal precision?</a> wanted with formtastic. Thanks!</p>