diff --git a/src/hello_world_project/example_module.py b/src/hello_world_project/example_module.py
index b389af8..57d8388 100644
--- a/src/hello_world_project/example_module.py
+++ b/src/hello_world_project/example_module.py
@@ -1,2 +1,50 @@
-def add_numbers(a: int, b: int) -> int:
-    return a + b
+from datetime import datetime
+def godz_dek(func):
+    def wrapper(*args, **kwargs):
+        print(f"[{datetime.now().strftime('%H:%M:%S')}]")
+        return func(*args, **kwargs)
+    return wrapper
+   
+class SimpleCalculator:
+    def add_numbers(self, a: float, b: float) -> float:
+        return a + b
+
+    def sub_numbers(self, a: float, b:float) -> float:
+        return a - b
+
+    def multiply_numbers(self, a: float, b: float) -> float:
+        return a * b
+
+    def div_numbers(self, a: float, b: float) -> float:
+        if(abs(b)>0.0001):
+            return a / b
+        else:
+            raise Exception
+       
+class ScientificCalc(SimpleCalculator):
+    def power_numbers(self, base, exp):
+        return base ** exp
+    def sqr_numbers(self, base):
+        return base ** 1/2
+
+class FinancialCalc(SimpleCalculator):
+    @godz_dek
+    def add_numbers(self, a: float, b: float) -> float:
+        return a + b
+    @godz_dek
+    def sub_numbers(self, a: float, b:float) -> float:
+        return a - b
+    @godz_dek
+    def multiply_numbers(self, a: float, b: float) -> float:
+        return a * b
+    @godz_dek
+    def div_numbers(self, a: float, b: float) -> float:
+        if(abs(b)>0.0001):
+            return a / b
+        else:
+            raise Exception
+    
+
+# def FactoryCalculator(type: str):
+#     factory = {"Simple": SimpleCalculator, "Science":ScientificCalc }
+#     return factory[type]()
\ No newline at end of file
diff --git a/src/hello_world_project/main.py b/src/hello_world_project/main.py
old mode 100644
new mode 100755
index c0f4cd6..ed63a77
--- a/src/hello_world_project/main.py
+++ b/src/hello_world_project/main.py
@@ -1,5 +1,6 @@
-from hello_world_project.utils import greet_user
-from hello_world_project.example_module import add_numbers
+#! usr/bin/python3
+from utils import greet_user
+import example_module 
 
 def main():
     print("=== Hello World Project ===")
@@ -8,8 +9,29 @@ def main():
     greeting = greet_user(name)
     print(greeting)
 
-    result = add_numbers(10, 5)
+    calc_dict={"b":example_module.SimpleCalculator, "s":example_module.ScientificCalc, "f":example_module.FinancialCalc}
+    calc_s= input("Enter b for basic\n, s for scientific\n and f for financial calculator:")
+    calc=calc_dict[calc_s]()
+    while True:
+        if calc_s == "b":
+            fun_dict_1={"a":example_module.SimpleCalculator.add_numbers,"s":example_module.SimpleCalculator.sub_numbers,"m":example_module.SimpleCalculator.multiply_numbers,"d":example_module.SimpleCalculator.div_numbers}
+            fun_s= input("Enter a for addition, \n s for subtraction, \nm for multiplication, \nd for division")
+            fun=fun_dict_1[fun_s]
+        elif calc_s == "s":
+            fun_dict_2={"a":example_module.ScientificCalc.add_numbers,"s":example_module.ScientificCalc.sub_numbers,"m":example_module.ScientificCalc.multiply_numbers,"d":example_module.ScientificCalc.div_numbers,"p":example_module.ScientificCalc.power_numbers,"q":example_module.ScientificCalc.sqr_numbers}
+            fun_s= input("Enter a for addition, \n s for subtraction, \nm for multiplication, \nd for division, \np for power, \nq for square_root ")
+            fun=fun_dict_2[fun_s]
+        else:
+            fun_dict_3={"a":example_module.FinancialCalc.add_numbers,"s":example_module.FinancialCalc.sub_numbers,"m":example_module.FinancialCalc.multiply_numbers,"d":example_module.FinancialCalc.div_numbers}
+            fun_s= input("Enter a for addition, \n s for subtraction, \nm for multiplication, \nd for division")
+            fun=fun_dict_3[fun_s]
+        a = float(input("Enter a: "))
+        b = float(input("Enter b: "))
+        print(fun(calc,a,b))
+    
+    result = example_module.SimpleCalculator().add_numbers(10, 5)
     print(f"The result of adding 10 and 5 is {result}.")
 
+
 if __name__ == "__main__":
     main()