gradebook MDL-22670 added a comment above a function to make its purpose more clear

grade/edit/tree/lib.php

@@ -377,6 +377,8 @@ class grade_edit_tree {
         }
     }
 
+    //Trim's trailing zeros. Used on the 'categories and items' page for grade items settings like aggregation co-efficient
+    //Grader report has its own decimal place settings so they are handled elsewhere
     function format_number($number) {
         return rtrim(rtrim(format_float($number, 4),'0'),'.');
     }