Oops, try again. It looks like your grades_sum function doesn't properly compute the sum of all the grades! It returned 1045.5 instead of 319 for grades_sum([95, 97, 39, 86, 2])

<- it displays this on the side, but there is an error message.

I expected the sum (as shown above) and no error message? ^^" Please let me know where I made a mistake!

```
grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]
def grades_sum(scores):
total = 0
for number in grades:
total += number
return total
print grades_sum(grades)
```