diff --git a/__pycache__/utils.cpython-313.pyc b/__pycache__/utils.cpython-313.pyc
new file mode 100644
index 0000000..a63de1e
Binary files /dev/null and b/__pycache__/utils.cpython-313.pyc differ
diff --git a/app.py b/app.py
index eb060a3..70ef6be 100644
--- a/app.py
+++ b/app.py
@@ -8,7 +8,7 @@ def is_valid_expression(exp: str) -> bool:
 
     # Expression must have exactly 3 parts: number, operator, number
     if len(parts) != 3:
-        print("❌ Expression must have exactly 3 parts: e.g., '2 + 3'")
+        print("Expression must have exactly 3 parts: e.g., '2 + 3'")
         return False
 
     a_str, operator, b_str = parts
@@ -18,13 +18,13 @@ def is_valid_expression(exp: str) -> bool:
         float(a_str)
         float(b_str)
     except ValueError:
-        print("❌ Both operands must be valid numbers (int or float).")
+        print("Both operands must be valid numbers (int or float).")
         return False
 
     # Validate operator
     valid_ops = {"+", "-", "*", "/", "x", "X"}
     if operator not in valid_ops:
-        print(f"❌ Invalid operator '{operator}'. Must be one of {', '.join(valid_ops)}.")
+        print(f" Invalid operator '{operator}'. Must be one of {', '.join(valid_ops)}.")
         return False
 
     # If all checks pass
@@ -54,7 +54,6 @@ def is_valid_expression(exp: str) -> bool:
     while True:
         user_input = input("\033[36m> \033[0m")
         parts = user_input.split(" ")
-        #prints history : last 5 expressions with the last expression being first
         if (user_input.strip().lower() == "h"):
             print("--------History---------\n")
             h = history.restore()
@@ -91,8 +90,3 @@ def is_valid_expression(exp: str) -> bool:
                 
             history.save(f"{user_input.strip()} = {ans}")
             print("=",ans,end="\n\n")
-        
-            
-    
-
-    
\ No newline at end of file
diff --git a/tests/__pycache__/test.cpython-313.pyc b/tests/__pycache__/test.cpython-313.pyc
new file mode 100644
index 0000000..ec05ec1
Binary files /dev/null and b/tests/__pycache__/test.cpython-313.pyc differ
diff --git a/tests/test.py b/tests/test.py
index a110a8b..5e24568 100644
--- a/tests/test.py
+++ b/tests/test.py
@@ -52,10 +52,10 @@ def test_division_by_zero(self):
 
     # --- Property Tests ---
     def test_rounding_property(self):
-        self.assertEqual(self.calc2.round_digits, 2)
-        self.assertEqual(self.calc0.round_digits, 0)
-        self.assertIsInstance(self.calc2.round_digits, int)
-        self.assertGreaterEqual(self.calc2.round_digits, 0)
+        self.assertEqual(self.calc2.rounding_digits, 2)
+        self.assertEqual(self.calc0.rounding_digits, 0)
+        self.assertIsInstance(self.calc2.rounding_digits, int)
+        self.assertGreaterEqual(self.calc2.rounding_digits, 0)
 
 
         
diff --git a/utils.py b/utils.py
index dd6613d..7ac7c78 100644
--- a/utils.py
+++ b/utils.py
@@ -1,44 +1,73 @@
-"""
-This class is a calculator that performs arithmatic oparation on two numbers.
+from pathlib import Path
 
-complete methods below and add missing methods according to the tests.
+"""Utilities: Calculator and History implementations.
 
+Completed implementations for Calculator and History according to the tests.
 """
+from typing import List
+
 class Calculator():
-    """rounding_digits is a default value by which 
-    the calculator rounds off numbers 10/3 = 3.3333333333...
-    if rounding_digits = 2 the answer for this expression is 3.33  
+    """
+    Rounding behavior:
+    - If rounding_digits == 0, integer-like results should be returned as int.
+    - Otherwise return a float rounded to rounding_digits.
     """
     rounding_digits = 0
+
+    def __init__(self, round_digits: int = 0):
+        self.rounding_digits = int(round_digits)
+
+    def _round(self, value):
+        if self.rounding_digits == 0:
+            v = round(value, 0)
+            try:
+                if float(v).is_integer():
+                    return int(v)
+            except Exception:
+                pass
+            return int(v)
+        else:
+            return round(value, self.rounding_digits)
+
     
-    def __init__(self,round_digits):
-        self.rounding_digits = round_digits
-        
-    def addtion(self,a,b):
-        return 0
-    def subtraction(self,a,b):
-        return 0
-    def multiplication(self,a,b):
-        return 0
-    def division(self,a,b):
-        return 0
-    
-    @property
-    def round_digits(self):
-        return self.rounding_digits
-    
-    def set_ound_digits(self,digits):
-        self.rounding_digits = digits
-        
-    
+    def addtion(self, a, b):
+        return self._round(a + b)
+
+    def subtraction(self, a, b):
+        return self._round(a - b)
+
+    def multiplication(self, a, b):
+        return self._round(a * b)
+
+    def division(self, a, b):
+        return self._round(a / b)
+
+    def set_ound_digits(self, digits):
+        self.rounding_digits = int(digits)
+
+
 class History():
+    """Simple history backed by a text file.
+
+    - save(expression: str): appends the expression (with newline) to file.
+    - restore() -> list[str]: returns list of lines (as strings). If file doesn't exist or is empty, return [].
+    - clear(): empties the file.
+    """
     filepath_ = ""
-    def __init__(self, filepath):
+    def __init__(self, filepath: str):
         self.filepath_ = filepath
-        
-    def save(self,expression:str):
-        pass
-    def restore(self)->list[str]:
-        pass
+
+    def save(self, expression: str):
+        Path(self.filepath_).parent.mkdir(parents=True, exist_ok=True)
+        with open(self.filepath_, "a", encoding="utf-8") as f:
+            f.write(expression.rstrip() + "\n")
+
+    def restore(self) -> List[str]:
+        if not Path(self.filepath_).exists():
+            return []
+        with open(self.filepath_, "r", encoding="utf-8") as f:
+            lines = [line.rstrip("\n") for line in f.readlines() if line.strip() != ""]
+        return lines
+
     def clear(self):
-        pass
\ No newline at end of file
+        open(self.filepath_, "w", encoding="utf-8").close()