title: How to round to nearest 0, 5 or 9 integer
body: <p>How to round a given number to a 0, 5 or 9, which ever is closest?
  I've tried with:</p>
  
  <pre><code>=MROUND(I2,5)-((MOD(MROUND(I2,5),10))=0)
  </code></pre>
  
  <p>But I need zeros too, this only gives me fives and nines.
  Thanks</p>