title: Variable subtraction in django templates
body: <p>It is able to write <code>{{ myval.add:5 }}</code>, <code>{{ myval|add:value }}</code> and even <code>{{ myval|add:-5 }}</code>.</p>
  
  <p>However, I can't find out what I should type to add value * -1 like <code>{{ myval|add:-value }}</code>. This doesn't work, sadly.</p>