simple python calculator

#Store number variables for the two numbers

num1 = input('Enter first number: ')
num2 = input('Enter second number: ')

#the sum of the two numbers variable
sum = float(num1) + float(num2)
sum2 = float(num1) - float(num2)
sum3 = float(num1) * float(num2)
sum4 = float(num1) / float(num2)

#what operator to use
choice = input('Enter an operator, + = addition, - = subtraction, * = multiplication and / = division: ')
#different sums based on the operators
if choice == '+':
  print('The sum of {0} and {1} is {2}'.format(num1, num2, sum))

  if choice == '-':
    print('The sum of {0} and {1} is {2}'.format(num1, num2, sum2))

if choice == '*':
    print('The sum of {0} and {1} is {2}'.format(num1, num2, sum3))

if choice == '/':
    print('The sum of {0} and {1} is {2}'.format(num1, num2, sum4))
 

def mutiply (x):
    return 5*x
o = mutiply(10)
print(o)

# Python program for simple calculator 
  
# Function to add two numbers  
def add(num1, num2): 
    return num1 + num2 
  
# Function to subtract two numbers  
def subtract(num1, num2): 
    return num1 - num2 
  
# Function to multiply two numbers 
def multiply(num1, num2): 
    return num1 * num2 
  
# Function to divide two numbers 
def divide(num1, num2): 
    return num1 / num2 
  
print("Please select operation -\n" \ 
        "1. Add\n" \ 
        "2. Subtract\n" \ 
        "3. Multiply\n" \ 
        "4. Divide\n") 
  
  
# Take input from the user  
select = input("Select operations form 1, 2, 3, 4 :") 
  
number_1 = int(input("Enter first number: ")) 
number_2 = int(input("Enter second number: ")) 
  
if select == '1': 
    print(number_1, "+", number_2, "=", 
                    add(number_1, number_2)) 
  
elif select == '2': 
    print(number_1, "-", number_2, "=", 
                    subtract(number_1, number_2)) 
  
elif select == '3': 
    print(number_1, "*", number_2, "=", 
                    multiply(number_1, number_2)) 
  
elif select == '4': 
    print(number_1, "/", number_2, "=", 
                    divide(number_1, number_2)) 
else: 
    print("Invalid input") 

def mutiply (x):
    return _*x
o = mutiply(_)
print(o)