I am stuck on functions

[wavic]

Well, first you have to create a variable which will hold the incrementing sum as you loop over the list. So:

sum = 0
For each number in the list:
    add the number to the sum
Then return the average 

This is a pretty basic usage of a loop so I doubt that you will face some obstacles. 
Another thing. You are calling the scorecalculator() function inside the while loop. Also, you have to assign the returned result to a variable because the function just returns something but this object is never used.

var = func()