diff --git a/change_log.txt b/change_log.txt
index 6e0c7aed4..4785e61dd 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -1,4 +1,7 @@
 ===== 3.1.31-dev ===== (xx.xx.xx)
+ 11.09.2016
+  - improvement {math} misleading E_USER_WARNING messages when parameter value = null https://github.com/smarty-php/smarty/issues/288
+
  09.09.2016
   - bugfix/optimization {foreach} did not execute the {foreachelse} when iterating empty objects https://github.com/smarty-php/smarty/pull/287
   - bugfix {foreach} must keep the @properties when restoring a saved $item variable as the properties might be used outside {foreach} https://github.com/smarty-php/smarty/issues/267
diff --git a/libs/plugins/function.math.php b/libs/plugins/function.math.php
index 655fe728d..fc5db335c 100644
--- a/libs/plugins/function.math.php
+++ b/libs/plugins/function.math.php
@@ -58,12 +58,28 @@ function smarty_function_math($params, $template)
         return;
     }
 
+    foreach ($params as $key => $val) {
+        if ($key != "equation" && $key != "format" && $key != "assign") {
+            // make sure value is not empty
+            if (strlen($val) == 0) {
+                trigger_error("math: parameter '{$key}' is empty", E_USER_WARNING);
+
+                return;
+            }
+            if (!is_numeric($val)) {
+                trigger_error("math: parameter '{$key}' is not numeric", E_USER_WARNING);
+
+                return;
+            }
+        }
+    }
+
     // match all vars in equation, make sure all are passed
     preg_match_all('!(?:0x[a-fA-F0-9]+)|([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)!', $equation, $match);
 
     foreach ($match[ 1 ] as $curr_var) {
         if ($curr_var && !isset($params[ $curr_var ]) && !isset($_allowed_funcs[ $curr_var ])) {
-            trigger_error("math: function call $curr_var not allowed", E_USER_WARNING);
+            trigger_error("math: function call '{$curr_var}' not allowed, or missing parameter '{$curr_var}'", E_USER_WARNING);
 
             return;
         }
@@ -71,17 +87,6 @@ function smarty_function_math($params, $template)
 
     foreach ($params as $key => $val) {
         if ($key != "equation" && $key != "format" && $key != "assign") {
-            // make sure value is not empty
-            if (strlen($val) == 0) {
-                trigger_error("math: parameter $key is empty", E_USER_WARNING);
-
-                return;
-            }
-            if (!is_numeric($val)) {
-                trigger_error("math: parameter $key: is not numeric", E_USER_WARNING);
-
-                return;
-            }
             $equation = preg_replace("/\b$key\b/", " \$params['$key'] ", $equation);
         }
     }