Now, make a function named summarize that also takes a list. It should return the string "The sum of X is Y."...

Joshua,

See my answer here, maybe it will help. https://teamtreehouse.com/forum/how-do-i-make-a-funcwtion-addlist-to-return-the-numbers-added-in-a-list-i-used-sum-but-cannot-write-in-a-function

you almost have it. you dont need to use join.

def add_list(another_list):
  return sum(another_list)

def summarize(another_list):
  return "The sum of {} is {}.".format(another_list, sum(another_list))

technically I think they want you to use the add_list function you defined first: instead of using the sum() function

def add_list(another_list):
  return sum(another_list)

def summarize(another_list):
  return "The sum of {} is {}.".format(another_list, add_list(another_list))

I am also having problems with this... I feel like my solution is similar to yours Stone Preston except i don't use sum(). My code is:

# add_list([1, 2, 3]) should return 6
# summarize([1, 2, 3]) should return "The sum of [1, 2, 3] is 6."

def add_list(list_of_nums):#takes one parameter which is a list of numbers
  for num in list_of_nums:
    i = 0
    total = list_of_nums[i] + list_of_nums[i +1]
    total = total + total
    i += 1
    return total

  def summarize(list_of_nums):
    return "The sum of {} is {}.".format(str(list_of_nums), add_list(list_of_nums))

when I submit this to be checked I am told that "Bummer! NameError: name 'summarize' is not defined". This doesn't make sense to me. Any suggestions Kenneth Love ?

def add_list(addlist): list_tot=0 for i in addlist: list_tot= addlist[0]+addlist[1]+addlist[2] return list_tot def summarize(s_list): return "The sum of {} is {}.".format(addlist,list_tot)