diff --git a/src/main/py/read_math_function.py b/src/main/py/read_math_function.py
index b51bb8a..0b2cdd9 100644
--- a/src/main/py/read_math_function.py
+++ b/src/main/py/read_math_function.py
@@ -3,8 +3,7 @@ def read_constant(type, value):
         return False
     if is_string(value):
         if is_allowed_string(type, value):
-            constant = calculate_string(value)
-            return constant
+            return calculate_string(value)
     return value