title: How to subtract two fields in django templates?
body: <p>Before marking as duplicate to numerous other questions on SO, read. I have three fields, <code>Credit Available</code>, <code>Credit Limit</code> and <code>Credit Balance</code>. I'm getting the values for <code>Credit Limit</code> and <code>Credit Balance</code> from my database. To display <code>Credit Available</code>, I want to do <code>Credit Limit</code>-<code>Credit Balance</code>. I tried doing this from other answers on stackoverflow, but they did not work</p>
  
  <pre><code>&lt;tr&gt;
      &lt;td style="text-align:center"&gt;{{ credit.credit_limit|add:"-{{credit.credit_balance}}" }}&lt;/td&gt;
      &lt;td align="center"&gt;{{ credit.credit_limit}}&lt;/td&gt;
      &lt;td align="center"&gt;{{ credit.credit_balance }}&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>Can I do this without writing new template tags or using the mathfilter module?</p>