I believe I am getting the correct average results, but I keep getting an error:

Oops, try again. grades_average([2]) returned 80.42307692307692 instead of the expected: 2.0

grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]

What's wrong!

def grades_sum(numbers):

total = 0

for item in numbers:

total += item

return total

def grades_average(scores):

sums = grades_sum(grades)

average = float(sums) / len(grades)

return average

print grades_average(grades)```