diff --git a/python/paddle/v2/fluid/layers/math_op_patch.py b/python/paddle/v2/fluid/layers/math_op_patch.py
index 5efc116db2ed0fd74613c8985d4f6b3bbdd0ff75..11197b70a3d4cae08afbb49ad31013ab40e4dad2 100644
--- a/python/paddle/v2/fluid/layers/math_op_patch.py
+++ b/python/paddle/v2/fluid/layers/math_op_patch.py
@@ -19,7 +19,7 @@ __all__ = ['monkey_patch_variable']
 
 
 def monkey_patch_variable():
-    def new_name():
+    def unique_tmp_name():
         return unique_name("tmp")
 
     def safe_get_dtype(var):
@@ -29,21 +29,9 @@ def monkey_patch_variable():
             raise ValueError("Cannot get data type from %s", var.name)
         return dtype
 
-    def create_scalar(block, value, dtype):
-        value = float(value)
-        tmp_name = new_name()
-        var = block.create_var(name=tmp_name, shape=[1], dtype=dtype)
-        block.append_op(
-            type="fill",
-            outputs={"Out": [var]},
-            attrs={"value": [value],
-                   "shape": [1],
-                   "dtype": dtype})
-        return var
-
     def create_tensor(block, value, dtype, shape):
         value = float(value)
-        tmp_name = new_name()
+        tmp_name = unique_tmp_name()
         var = block.create_var(name=tmp_name, shape=shape, dtype=dtype)
         block.append_op(
             type="fill_constant",
@@ -53,10 +41,13 @@ def monkey_patch_variable():
                    'value': value})
         return var
 
+    def create_scalar(block, value, dtype):
+        return create_tensor(block, value, dtype, shape=[1])
+
     def create_tensor_with_batchsize(ref_var, value, dtype):
         assert isinstance(ref_var, Variable)
         value = float(value)
-        tmp_name = new_name()
+        tmp_name = unique_tmp_name()
         var = ref_var.block.create_var(name=tmp_name, dtype=dtype)
         ref_var.block.append_op(
             type='fill_constant_batch_size_like',
@@ -68,7 +59,7 @@ def monkey_patch_variable():
 
     def astype(self, dtype):
         """
-        Cast a variable to data type.
+        Cast a variable to a specified data type.
         NOTE: The variable must be a Tensor
         Args:
             self(Variable): The source variable
@@ -77,7 +68,7 @@ def monkey_patch_variable():
         Returns:
             Variable with new dtype
         """
-        tmp_name = new_name()
+        tmp_name = unique_tmp_name()
         out = self.block.create_var(name=tmp_name, dtype=dtype)
         self.block.append_op(
             type="cast",
@@ -120,7 +111,7 @@ def monkey_patch_variable():
                 self = other_var
                 other_var = tmp
 
-            tmp_name = new_name()
+            tmp_name = unique_tmp_name()
             out = self.block.create_var(name=tmp_name, dtype=lhs_dtype)
             self.block.append_op(
                 type=op_type,