old_contents: ```python
  
  i = -1
  sum = 0
  
  one_to_ten = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  
  while i < 10:
  	i += 1
  	sum += one_to_ten[i]
  
  print(sum)
  
  ```
new_contents: ```python
  
  i = -1
  sum = 0
  
  one_to_ten = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  
  while i < 10:
  	i += 1
  	sum += one_to_ten[i]
  
  print(sum)
  
  ```
  
  **Make function!**
  `like:`
  ```python
  def sum(number):
      # .. TODO
      return 0
  ```
  
  `I want to reuse this function, like:`
  ```python
  one_to_ten = sum(range(1,11))
  one_to_five = sum(range(1,6))
  five_to_ten = sum(range(5,11))
  ```
  
subject: Make function! and Use 4 tabs, not 8 tabs.