diff --git a/jedi/evaluate/compiled/__init__.py b/jedi/evaluate/compiled/__init__.py
index 8db4db07..7a3eaf52 100644
--- a/jedi/evaluate/compiled/__init__.py
+++ b/jedi/evaluate/compiled/__init__.py
@@ -312,6 +312,10 @@ class Builtin(CompiledObject, IsScope):
         # access it.
         return [d for d in super(Builtin, self).get_defined_names() if d.name != 'None']
 
+    def get_by_name(self, name):
+        item = [n for n in self.get_defined_names() if n.get_code() == name][0]
+        return item.parent
+
 
 def _a_generator(foo):
     """Used to have an object to return for generators."""
diff --git a/jedi/evaluate/precedence.py b/jedi/evaluate/precedence.py
index 5b12d992..aebedb59 100644
--- a/jedi/evaluate/precedence.py
+++ b/jedi/evaluate/precedence.py
@@ -174,6 +174,19 @@ def _check_operator(iterator, priority=PythonGrammar.LOWEST_PRIORITY):
     return left
 
 
+def _literals_to_types(evaluator, result):
+    # Changes literals ('a', 1, 1.0, etc) to its type instances (str(),
+    # int(), float(), etc).
+    for i, r in enumerate(result):
+        if is_literal(r):
+            # Literals are only valid as long as the operations are
+            # correct. Otherwise add a value-free instance.
+            cls = builtin.get_by_name(r.name)
+            from jedi.evaluate import representation as er
+            result[i] = er.Instance(evaluator, cls)
+    return list(set(result))
+
+
 def calculate(evaluator, left_result, operator, right_result):
     result = []
     if left_result is None and right_result:
@@ -185,18 +198,18 @@ def calculate(evaluator, left_result, operator, right_result):
         if not left_result or not right_result:
             # illegal slices e.g. cause left/right_result to be None
             result = (left_result or []) + (right_result or [])
-            for i, r in enumerate(result):
-                if _is_number(r) or _is_string(r):
-                    # Literals are only valid as long as the operations are
-                    # correct. Otherwise add a value-free instance.
-                    cls = CompiledObject(type(r.obj), builtin)
-                    from jedi.evaluate import representation as er
-                    result[i] = er.Instance(evaluator, cls)
+            result = _literals_to_types(evaluator, result)
         else:
-            for left in left_result:
-                for right in right_result:
-                    result += _element_calculate(evaluator, left, operator, right)
-    return list(set(result))
+            # I don't think there's a reasonable chance that a string
+            # operation is still correct, once we pass something like six
+            # objects.
+            if len(left_result) * len(right_result) > 6:
+                result = _literals_to_types(evaluator, left_result + right_result)
+            else:
+                for left in left_result:
+                    for right in right_result:
+                        result += _element_calculate(evaluator, left, operator, right)
+    return result
 
 
 def _factor_calculate(evaluator, operator, right):
@@ -216,6 +229,10 @@ def _is_string(obj):
         and isinstance(obj.obj, (str, unicode))
 
 
+def is_literal(obj):
+    return _is_number(obj) or _is_string(obj)
+
+
 def _element_calculate(evaluator, left, operator, right):
     if operator == '*':
         # for iterables, ignore * operations
diff --git a/test/speed/precedence.py b/test/speed/precedence.py
index 5f0c9144..bfc2c6fb 100644
--- a/test/speed/precedence.py
+++ b/test/speed/precedence.py
@@ -33,5 +33,5 @@ def ret(code5):
 
 
 def call(code3):
-    code3 = '1' + ret(code3)
+    code3 = ret(ret('1')) + ret(code3)
     code3.partition