--- moodleform_mod.php.bak  2017-10-23 11:55:34.222730195 +0700
+++ moodleform_mod.php      2017-10-23 11:46:27.092834648 +0700
@@ -408,7 +408,7 @@
             } else {
                 $grade = $scale;
             }
-            if ($data['gradepass'] > $grade) {
+            if (unformat_float($data['gradepass']) > $grade) {
                 $errors['gradepass'] = get_string('gradepassgreaterthangrade', 'grades', $grade);
             }
         }