Get Meta_Value from WP database

I'm trying to do a database query that will return the meta_value of a particular row in the postmeta table based on the post ID. Then pass the variable as an integer to a jQuery variable. Here's what my code looks like:

function getListings() {
  var value3 = jQuery("#input_1_3").val();
  if (value3 === 'something')  {
    value3 = <?php echo $wpdb->get_var( "SELECT meta_value 
    FROM $wpdb->postmeta WHERE post_id = 11" ); 
    ?>;
  }
}

Right now it's returning a weird series of numbers and a ";"...The result I need should be an integer.

Any help would be greatly appreciated. I'm sure it's something obvious, but don't know what.

UPDATED:

Here is a screenshot of one of the tables I'm trying to get a meta_value from. The value I want to retrieve is "5".