def calculator(): print("Simple Calculator") print("1. Addition") print("2. Subtraction") print("3. Multiplication") print("4. Division") choice = input("Enter your choice (1/2/3/4): ") num1 = float(input("Enter first number: ")) num2 = float(input("Enter second number: ")) if choice == '1': print(num1, "+", num2, "=", num1 + num2) elif choice == '2': print(num1, "-", num2, "=", num1 - num2) elif choice == '3': print(num1, "*", num2, "=", num1 * num2) elif choice == '4': if num2 != 0: print(num1, "/", num2, "=", num1 / num2) else: print("Error! Division by zero is not allowed.") else: print("Invalid choice.") calculator() ```