I dont understand what is the problem with my code. Invalid literal error


#1
     def add(numbers):
    a = 0
        for num in numbers:
        a += num
        return a
        add_numbers = []
        def subtract(numbers):
            b = 0
            for num in numbers:
                b -= num
            return b
        sub_numbers = []
        def multiply(numbers):
            c = 0
            for num in numbers:
                c *= num
            return c
        mul_numbers = []
        def divide(numbers):
            d = 0
            for num in numbers:
                d /= num
            return d
        div_numbers = []
        print("What do you want do?")
        print("1.Add")
        print("2.Subtract")
        print("3.Multiply")
        print("4.Divide")
        time.sleep(1)
        print("...")
        print("An addition expression is something like 3+5+7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A subtraction expression is something like 3-5-7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A multiplication expression is something like 3*5*7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A division expression is something like 3/5/7 (no spaces)")
        print("...")
        time.sleep(1)
        choice = input("Enter choice(1/2/3/4):")
        time.sleep(2)
        print("Checking if %s is a valid choice..." % (choice))
        print("...")
        while 1:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            add_numbers = []
            for item in my_string:
                add_numbers.append(int(item)) # Convert to int and append to add_numbers.
            result = add(add_numbers) # add it all up and assign to result.
            print ("=" (result))
            if add(add_numbers) >= 1000:
                break
        while 2:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            sub_numbers = []
            for item in my_string:
                sub_numbers.append(int(item)) # Convert to int and append to sub_numbers.
            result = subtract(sub_numbers) # add it all up and assign to result.
            print ("=" (result))
            if subtract(sub_numbers) >= 100:
                break
        while 3:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            mul_numbers = []
            for item in my_string:
                mul_numbers.append(int(item)) # Convert to int and append to my_numbers.
            result = multiply(mul_numbers) # add it all up and assign to result.
            print ("=" (result))
            if multiply(mul_numbers) >= 10000:
                break
        while 4:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            div_numbers = []
            for item in my_string:
                div_numbers.append(int(item)) # Convert to int and append to my_numbers.
            result = divide(div_numbers) # add it all up and assign to result.
            print ("=" (result))
            if divide(div_numbers) >= 100:
                break
def add(numbers):
    a = 0
        for num in numbers:
        a += num
        return a
        add_numbers = []
        def subtract(numbers):
            b = 0
            for num in numbers:
                b -= num
            return b
        sub_numbers = []
        def multiply(numbers):
            c = 0
            for num in numbers:
                c *= num
            return c
        mul_numbers = []
        def divide(numbers):
            d = 0
            for num in numbers:
                d /= num
            return d
        div_numbers = []
        print("What do you want do?")
        print("1.Add")
        print("2.Subtract")
        print("3.Multiply")
        print("4.Divide")
        time.sleep(1)
        print("...")
        print("An addition expression is something like 3+5+7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A subtraction expression is something like 3-5-7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A multiplication expression is something like 3*5*7 (no spaces)")
        print("...")
        time.sleep(1)
        print("A division expression is something like 3/5/7 (no spaces)")
        print("...")
        time.sleep(1)
        choice = input("Enter choice(1/2/3/4):")
        time.sleep(2)
        print("Checking if %s is a valid choice..." % (choice))
        print("...")
        while 1:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            add_numbers = []
            for item in my_string:
                add_numbers.append(int(item)) # Convert to int and append to add_numbers.
            result = add(add_numbers) # add it all up and assign to result.
            print ("=" (result))
            if add(add_numbers) >= 1000:
                break
        while 2:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            sub_numbers = []
            for item in my_string:
                sub_numbers.append(int(item)) # Convert to int and append to sub_numbers.
            result = subtract(sub_numbers) # add it all up and assign to result.
            print ("=" (result))
            if subtract(sub_numbers) >= 100:
                break
        while 3:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            mul_numbers = []
            for item in my_string:
                mul_numbers.append(int(item)) # Convert to int and append to my_numbers.
            result = multiply(mul_numbers) # add it all up and assign to result.
            print ("=" (result))
            if multiply(mul_numbers) >= 10000:
                break
        while 4:
            my_string = input("Type in numbers: ")
            my_string = my_string.split()
            div_numbers = []
            for item in my_string:
                div_numbers.append(int(item)) # Convert to int and append to my_numbers.
            result = divide(div_numbers) # add it all up and assign to result.
            print ("=" (result))
            if divide(div_numbers) >= 100:
                break