title: I get this syntax error: TypeError: unsupported operand type(s) for +: 'int' and 'str'
body: <p>this is the problem i have to answer: </p>
  
  <p>Write a program to input exam scores (out of 100) until you enter 'quit'. After you finish entering exam scores the program will print out the average of all the exam scores.</p>
  
  <p>HINTS:
  To figure out the average you must keep a running total of exam scores and a count of the number entered.
  Try to make the program work 1 time, then figure out the exit condition and use a while True: loop.</p>
  
  <p>Example Run:
  Enter exam score or type 'quit': 100
  Enter exam score or type 'quit': 100
  Enter exam score or type 'quit': 50
  Enter exam score or type 'quit': quit
  Number of scores 3. Average is 83.33</p>
  
  <p>This is my code:</p>
  
  <pre><code>count = 0
  average = sum
  while True:
      num =input('Enter an exam score or type "quit":')
      count = count + 1
      average = sum(num)
      print ('the total of exams is %d and the average is %f' % count, average)
      if num == 'quit':
          break
  print ('this is ok for now')
  </code></pre>