title: How to truncate a number to 3 decimals
body: <p>I do not know how to round a number in MongoDB. I only find how to do it with 2 decimals but not with more decimals. </p>
  
  <pre><code>"location" : {
      "type" : "Point",
      "coordinates" : [ 
          -74.00568, 
          40.70511
      ]
  }
  </code></pre>
  
  <p>These is an example of a coordinate that I need to round with 3 numbers after the dot.
  Thank you</p>