diff --git a/ch08-arrays.rb b/ch08-arrays.rb
new file mode 100644
index 000000000..ebe66878a
--- /dev/null
+++ b/ch08-arrays.rb
@@ -0,0 +1,24 @@
+# Type as many words as we want (one word per line), continuing until we press Enter on an empty line
+# Repeat the words back to us in alphabetical order.
+# Test program thoroughly.
+
+words = []
+puts "Hello, why don't you type some lines? Enter one word per line. When you get fed up, press Enter on an empty line."
+
+userInputEmpty = false
+
+while userInputEmpty == false
+
+  word = gets.chomp
+
+  if word != ""
+    words.push word
+    puts "How about another word? Leave empty if you're done"
+
+  else
+    userInputEmpty = true
+  end
+end
+
+puts "And here is a lovely alphabetical list of your words!"
+puts words.sort
diff --git a/ch09-writing-your-own-methods/ask.rb b/ch09-writing-your-own-methods/ask.rb
index 01716eb35..23e9a058d 100644
--- a/ch09-writing-your-own-methods/ask.rb
+++ b/ch09-writing-your-own-methods/ask.rb
@@ -1,3 +1,39 @@
 def ask question
-  # your code here
-end
\ No newline at end of file
+  while true
+    puts question
+    reply = gets.chomp.downcase
+
+    if (reply == "yes" || reply == "no")
+      if reply == "yes"
+          return true
+      else
+          return false
+      end
+      break
+    else
+      puts 'Please answer "yes" or "no".'
+
+    end
+  end
+
+  answer
+end
+
+puts "Hello, and thank you for participating."
+puts
+
+ask "Do you like eating tacos?"
+ask "Do you like eating burritos?"
+wets_bed = ask "Do you wet the bed?"
+ask "Do you like eating chimichangas?"
+ask "Do you like eating sopapillas?"
+puts "Just a few more questions..."
+ask "Do you like drinking horchata?"
+ask "Do you like eating flautas?"
+
+puts
+puts "DEBRIEFING"
+puts "Thanks for taking part. Actually it wasn't about mexican food; it was about bed wetting."
+puts
+puts "And your answer to that question was..."
+puts wets_bed
diff --git a/ch09-writing-your-own-methods/old_school_roman_numerals.rb b/ch09-writing-your-own-methods/old_school_roman_numerals.rb
index ca6589f2d..7153aa0c2 100644
--- a/ch09-writing-your-own-methods/old_school_roman_numerals.rb
+++ b/ch09-writing-your-own-methods/old_school_roman_numerals.rb
@@ -1,3 +1,48 @@
+# Write a method that when passed an integer between 1 and 3000 (or so)
+# returns a string containing the proper old-school Roman numeral.
+
+# M = 1000
+# D = 500
+# C = 100
+# L = 50
+# X = 10
+# V = 5
+# I = 1
+
+# Hint: use the integer division and modulus methods
+
+# How many times does each of those roman numerals factor into numberRequested?
+
+# Example: 1759
+
+# 1 x 1000 = M
+# 1 x 500 = D
+# 2 x 100 = CC
+# 1 x 50 = L
+# 0 x 10 = no Xs
+# 1 x 5 = V
+# 4 x 1 = IIII
+
+# MDCCLVIIII
+
+# How many times does 1,000 go into it? Put that many Ms.
+# How many times does 500 go into the remainder? Put that many Ds.
+# How many times does 100 go into the remainder? Put that many Cs.
+# How many times does 50 go into the remainder? Put that many Ls.
+# How many times does 10 go into the remainder? Put that many Xs.
+# How many times does 5 go into the remainder? Put that many Vs.
+# How many times does 1 go into the remainder? Put that many Is.
+
 def old_roman_numeral num
-  # your code here
-end
\ No newline at end of file
+
+  numberMs = "M" * (num / 1000)
+  numberDs = "D" * ((num % 1000) / 500)
+  numberCs = "C" * ((num % 500) / 100)
+  numberLs = "L" * ((num % 100) / 50)
+  numberXs = "X" * ((num % 50) / 10)
+  numberVs = "V" * ((num % 10) / 5)
+  numberIs = "I" * ((num % 5) / 1)
+
+  return numberMs + numberDs + numberCs + numberLs + numberXs + numberVs + numberIs
+
+end
diff --git a/ch09-writing-your-own-methods/roman_numerals.rb b/ch09-writing-your-own-methods/roman_numerals.rb
index 5c93b59ac..d8a91d9db 100644
--- a/ch09-writing-your-own-methods/roman_numerals.rb
+++ b/ch09-writing-your-own-methods/roman_numerals.rb
@@ -1,3 +1,54 @@
+# M = 1000
+# D = 500
+# C = 100
+# L = 50
+# X = 10
+# V = 5
+# I = 1
+
 def roman_numeral num
-  # your code here
-end
\ No newline at end of file
+
+  number1000s = (num / 1000)
+  number100s = (num % 1000) / 100
+  number10s = (num % 100) / 10
+  number1s = (num % 10) / 1
+
+  numberDs = (num % 1000) / 500
+  numberCs = (num % 500) / 100
+  numberLs = (num % 100) / 50
+  numberXs = (num % 50) / 10
+  numberVs = (num % 10) / 5
+  numberIs = (num % 5) / 1
+
+  result = "M" * number1000s
+
+  if number100s == 9
+    result = result + "CM"
+  elsif number100s == 4
+    result = result + "CD"
+  else
+    result = result + "D" * numberDs
+    result = result + "C" * numberCs
+  end
+
+  if number10s == 9
+    result = result + "XC"
+  elsif number10s == 4
+    result = result + "XL"
+  else
+    result = result + "L" * numberLs
+    result = result + "X" * numberXs
+  end
+
+  if number1s == 9
+    result = result + "IX"
+  elsif number1s == 4
+    result = result + "IV"
+  else
+    result = result + "V" * numberVs
+    result = result + "I" * numberIs
+  end
+
+  result
+
+end
diff --git a/ch10-nothing-new/dictionary_sort.rb b/ch10-nothing-new/dictionary_sort.rb
index c9893d0fd..eadc70253 100644
--- a/ch10-nothing-new/dictionary_sort.rb
+++ b/ch10-nothing-new/dictionary_sort.rb
@@ -1,3 +1,42 @@
+# Okay how do we solve this in English?
+# For the purpose of comparison, we should just downcase everything
+# But if it were capitalised to begin with, it ought to remain so
+
 def dictionary_sort arr
-  # your code here
-end
\ No newline at end of file
+  recursive_sort arr, []
+end
+
+def recursive_sort unsorted_array, sorted_array
+
+  # If the unsorted array has no items in it, return the sorted array
+  if unsorted_array.length <= 0
+    return sorted_array
+  end
+
+  # Remove the last word from the unsorted array and put it into the variable smallest
+  smallest = unsorted_array.pop
+
+  # Create a new array called still_unsorted to hold all the other words
+  still_unsorted = []
+
+  # For each word in the unsorted array, see if it's smaller than the 'smallest' word that you took earlier
+  # If it is, put the smallest word back into the array, and replace 'smallest' with this new word
+  # If word is not smaller than the smallest, then push this word into the still unsorted array
+
+  unsorted_array.each do | word |
+
+    if word.downcase < smallest.downcase
+      still_unsorted.push smallest
+      smallest = word
+    else
+      still_unsorted.push word
+    end
+  end
+
+  # Put the smallest word into the sorted array
+  sorted_array.push smallest
+
+  # Now call the same recursive sort method to sort out the still_unsorted words
+  recursive_sort still_unsorted, sorted_array
+
+end
diff --git a/ch10-nothing-new/english_number.rb b/ch10-nothing-new/english_number.rb
index c0129bc4e..378814c7c 100644
--- a/ch10-nothing-new/english_number.rb
+++ b/ch10-nothing-new/english_number.rb
@@ -1,3 +1,90 @@
 def english_number number
-  # your code here
+  if number < 0
+    return "Please enter a number that isn't negative."
+  end
+
+  if number == 0
+    return "zero"
+  end
+
+  num_string = ""
+
+  ones_place = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
+  tens_place = ['ten', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety']
+  teenagers = ['eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']
+  zillions = [['hundred',2],
+              ['thousand', 3],
+              ['million', 6],
+              ['billion', 9],
+              ['trillion', 12],
+              ['quadrillion', 15],
+              ['quintillion', 18],
+              ['sextillion', 21],
+              ['septillion', 24],
+              ['octillion', 27],
+              ['nonillion', 30],
+              ['decillion', 33],
+              ['undecillion', 36],
+              ['duodecillion', 39],
+              ['tredecillion', 42],
+              ['quattuordecillion', 45],
+              ['quindecillion', 48],
+              ['sexdicillion', 51],
+              ['septendecillion', 54],
+              ['octodecillion', 57],
+              ['novembdecillion', 60],
+              ['vigintillion', 63],
+              ['googol', 100]]
+
+  left = number
+
+  while zillions.length > 0
+    zil_pair = zillions.pop
+    zil_name = zil_pair[0]
+    zil_base = 10 ** zil_pair[1]
+    write = left/zil_base
+    left = left - write*zil_base
+
+    if write > 0
+      prefix = english_number write
+      num_string = num_string + prefix + " " + zil_name
+      if left > 0
+        num_string = num_string + " "
+      end
+    end
+  end
+
+  write = left/10
+  left = left - write*10
+
+  if write > 0
+    if ((write == 1) and (left > 0))
+      num_string = num_string + teenagers[left-1]
+      left = 0
+    else
+      num_string = num_string + tens_place[write-1]
+    end
+
+    if left > 0
+      num_string = num_string + "-"
+    end
+  end
+
+  write = left
+  left = 0
+
+  if write > 0
+    num_string = num_string + ones_place[write-1]
+  end
+
+  num_string
+
 end
+
+# puts english_number 937234827364876238423423487686234
+# puts english_number 234987234982398798423
+# puts english_number 23432
+puts english_number 99
+puts english_number 234
+puts english_number 109238745102938560129834709285360238475982374561034
+# puts english_number 9898176572634765762999987987
diff --git a/ch10-nothing-new/ninety_nine_bottles_of_beer.rb b/ch10-nothing-new/ninety_nine_bottles_of_beer.rb
index 801de24bd..d9cb3aa2f 100644
--- a/ch10-nothing-new/ninety_nine_bottles_of_beer.rb
+++ b/ch10-nothing-new/ninety_nine_bottles_of_beer.rb
@@ -1 +1,98 @@
-# your code here
\ No newline at end of file
+def english_number number
+  if number < 0
+    return "Please enter a number that isn't negative."
+  end
+
+  if number == 0
+    return "zero"
+  end
+
+  num_string = ""
+
+  ones_place = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
+  tens_place = ['ten', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety']
+  teenagers = ['eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']
+  zillions = [['hundred',2],
+              ['thousand', 3],
+              ['million', 6],
+              ['billion', 9],
+              ['trillion', 12],
+              ['quadrillion', 15],
+              ['quintillion', 18],
+              ['sextillion', 21],
+              ['septillion', 24],
+              ['octillion', 27],
+              ['nonillion', 30],
+              ['decillion', 33],
+              ['undecillion', 36],
+              ['duodecillion', 39],
+              ['tredecillion', 42],
+              ['quattuordecillion', 45],
+              ['quindecillion', 48],
+              ['sexdicillion', 51],
+              ['septendecillion', 54],
+              ['octodecillion', 57],
+              ['novembdecillion', 60],
+              ['vigintillion', 63],
+              ['googol', 100]]
+
+  left = number
+
+  while zillions.length > 0
+    zil_pair = zillions.pop
+    zil_name = zil_pair[0]
+    zil_base = 10 ** zil_pair[1]
+    write = left/zil_base
+    left = left - write*zil_base
+
+    if write > 0
+      prefix = english_number write
+      num_string = num_string + prefix + " " + zil_name
+      if left > 0
+        num_string = num_string + " "
+      end
+    end
+  end
+
+  write = left/10
+  left = left - write*10
+
+  if write > 0
+    if ((write == 1) and (left > 0))
+      num_string = num_string + teenagers[left-1]
+      left = 0
+    else
+      num_string = num_string + tens_place[write-1]
+    end
+
+    if left > 0
+      num_string = num_string + "-"
+    end
+  end
+
+  write = left
+  left = 0
+
+  if write > 0
+    num_string = num_string + ones_place[write-1]
+  end
+
+  num_string
+
+end
+
+def bottles_of_beer num
+  while num > 0
+    english_num = english_number num
+    puts english_num.capitalize + " bottles of beer on the wall, " + english_num  + " bottles of beer!"
+    english_num = english_number num-1
+    num -= 1
+    if num == 0
+      puts "Take one down, pass it around, no more bottles of beer on the wall"
+    else
+      puts "Take one down, pass it around, " + english_num + " bottles of beer on the wall"
+    end
+  end
+end
+
+bottles_of_beer 99
diff --git a/ch10-nothing-new/shuffle.rb b/ch10-nothing-new/shuffle.rb
index a486ad94c..eab10598a 100644
--- a/ch10-nothing-new/shuffle.rb
+++ b/ch10-nothing-new/shuffle.rb
@@ -1,3 +1,44 @@
+# How would I shuffle an array in English?
+# Take a random item from the given array and put it in the new array
+# Keep going until all the items have moved from the given array into the new array
+
 def shuffle arr
-  # your code here
-end
\ No newline at end of file
+  recursive_shuffle arr, []
+end
+
+def recursive_shuffle original_array, shuffled_array
+
+  if original_array.length <= 0
+    return shuffled_array
+  end
+
+  # Remove the last item from the original array
+  randomWord = original_array.pop
+
+  # Insert it in a random place in the shuffled array
+  shuffled_array.insert(rand(shuffled_array.length+1), randomWord)
+
+  # Call the method again until all the elements have been shuffled
+  recursive_shuffle original_array, shuffled_array
+end
+
+
+#def shuffle arr # Chris Pine's shuffle method
+# shuf = []
+# while arr.length > 0
+#   rand_index = rand(arr.length)
+#   curr_index = 0
+#   new_arr = []
+#
+#   arr.each do |item|
+#     if curr_index == rand_index
+#       shuf.push item
+#     else
+#       new_arr.push item
+#     end
+#   curr_index += 1
+#   end
+#   arr = new_arr
+# end
+# shuf
+#end
diff --git a/ch10-nothing-new/sort.rb b/ch10-nothing-new/sort.rb
index 44c6deb58..67768c8c4 100644
--- a/ch10-nothing-new/sort.rb
+++ b/ch10-nothing-new/sort.rb
@@ -1,3 +1,47 @@
+# Which of two words comes first in the dictionary (using <)
+# Keep a list of already-sorted words, the other is a list of still-unsorted words
+#Take our list of words, find the smallest word (that would come first in the dictionary)
+# and stick it at the end of the alread-sorted list
+# All of the other words go into the still unsorted list
+# Then do the same thing still using the unsrted list instead of your original listFind the msallest words
+# Move it to the sorted list
+# Move the rest to the unsorted list
+# Keep going until your still-unsorted list is empty
+
 def sort arr
-  # your code here
-end
\ No newline at end of file
+  recursive_sort arr, []
+end
+
+def recursive_sort unsorted_array, sorted_array
+
+  # If the unsorted array has no items in it, return the sorted array
+  if unsorted_array.length <= 0
+    return sorted_array
+  end
+
+  # Remove the last word from the unsorted array and put it into the variable smallest
+  smallest = unsorted_array.pop
+
+  # Create a new array called still_unsorted to hold all the other words
+  still_unsorted = []
+
+  # For each word in the unsorted array, see if it's smaller than the 'smallest' word that you took earlier
+  # If it is, put the smallest word back into the array, and replace 'smallest' with this new word
+  # If word is not smaller than the smallest, then push this word into the still unsorted array
+
+  unsorted_array.each do | word |
+    if word < smallest
+      still_unsorted.push smallest
+      smallest = word
+    else
+      still_unsorted.push word
+    end
+  end
+
+  # Put the smallest word into the sorted array
+  sorted_array.push smallest
+
+  # Now call the same recursive sort method to sort out the still_unsorted words
+  recursive_sort still_unsorted, sorted_array
+
+end
diff --git a/ch11-reading-and-writing/build_a_better_playlist.rb b/ch11-reading-and-writing/build_a_better_playlist.rb
index 3b31bd241..1df218d2e 100644
--- a/ch11-reading-and-writing/build_a_better_playlist.rb
+++ b/ch11-reading-and-writing/build_a_better_playlist.rb
@@ -1,3 +1,38 @@
 def music_shuffle filenames
-  # your code here
+
+  filenames = filenames.sort
+  len = filenames.length
+
+  2.times do
+    l_idx = 0 # index of next card in left pile
+    r_idx = len/2 # index of next card in right pile
+    shuf = []
+
+    while shuf.length < len
+      if shuf.length%2 == 0
+        shuf.push(filenames[r_idx])
+        r_idx = r_idx + 1
+      else
+        shuf.push(filenames[l_idx])
+        l_idx = l_idx + 1
+      end
+    end
+
+    filenames = shuf
+  end
+
+  arr = []
+  cut = rand(len) # index of card to cut at
+  idx = 0
+
+  while idx < len
+    arr.push(filenames[(idx+cut)%len])
+    idx = idx + 1
+  end
+
+  arr
 end
+
+songs = ['aa/bbb', 'aa/ccc', 'aa/ddd', 'AAA/xxxx', 'AAA/yyyy', 'AAA/zzzz', 'foo/bar']
+
+puts(music_shuffle(songs))
diff --git a/ch11-reading-and-writing/build_your_own_playlist.rb b/ch11-reading-and-writing/build_your_own_playlist.rb
index 801de24bd..75e77a6f0 100644
--- a/ch11-reading-and-writing/build_your_own_playlist.rb
+++ b/ch11-reading-and-writing/build_your_own_playlist.rb
@@ -1 +1,39 @@
-# your code here
\ No newline at end of file
+def shuffle arr
+  recursive_shuffle arr, []
+end
+
+def recursive_shuffle original_array, shuffled_array
+
+  if original_array.length <= 0
+    return shuffled_array
+  end
+
+  random_element = original_array.pop
+  shuffled_array.insert(rand(shuffled_array.length+1), random_element)
+  recursive_shuffle original_array, shuffled_array
+end
+
+audio_files = Dir["../**/*.{MP3,mp3}"]
+
+if audio_files.length == 0
+  puts "I'm sorry, I couldn't find any audio files in your collection."
+else
+  puts "I found #{audio_files.length} audio files in your collection."
+  puts "What do you want to call your playlist?"
+  playlist_name = gets.chomp
+  playlist_name += ".m3u"
+
+  shuffled_files = []
+  shuffled_files = shuffle audio_files
+
+  playlist = ""
+
+  shuffled_files.each do |filename|
+    playlist += filename + "\n"
+  end
+
+  File.open playlist_name, 'w' do |f|
+    f.write playlist
+    puts "I just wrote you a file called #{playlist_name}. Enjoy!"
+  end
+end
diff --git a/ch11-reading-and-writing/safer_picture_downloading.rb b/ch11-reading-and-writing/safer_picture_downloading.rb
index 801de24bd..7ae7caa54 100644
--- a/ch11-reading-and-writing/safer_picture_downloading.rb
+++ b/ch11-reading-and-writing/safer_picture_downloading.rb
@@ -1 +1,36 @@
-# your code here
\ No newline at end of file
+pic_names = Dir["../*.{JPG,jpg}"] # Search in the parent directory
+
+puts "What would you like to call this batch?"
+batch_name = gets.chomp
+
+puts
+print "Downloading #{pic_names.length} files: "
+
+pic_number = 1
+
+pic_names.each do |name|
+  print "."
+  new_name = if pic_number < 10
+    "#{batch_name}0#{pic_number}.jpg"
+    else
+      "#{batch_name}#{pic_number}.jpg"
+  end
+  if File.exist? new_name
+    overwrite = gets.chomp "A file already exists with the name " + new_name + ". Do you want to overwrite? Type \"Yes\" or \"No\"."
+    if overwrite.downcase == "yes"
+      File.rename name, new_name
+      pic_number += 1
+    elsif overwrite.downcase == "no"
+      puts "Skipping " + new_name + " because it already exists."
+    end
+  end
+end
+
+puts
+puts "Done, cutie!"
+
+# TO DO
+# Add safety features to sure you never overwrite a file
+# File.exist? (pass it a filename and it will return true or false)
+# exit - kills your program right where it stands - good for spitting out an error message and then quitting
+# ßSolve this in English first Frances!
diff --git a/ch12-new-classes-of-objects/birthdates.txt b/ch12-new-classes-of-objects/birthdates.txt
new file mode 100644
index 000000000..ea3492642
--- /dev/null
+++ b/ch12-new-classes-of-objects/birthdates.txt
@@ -0,0 +1,8 @@
+Christopher Alexander, Oct 4, 1936
+Christopher Lambert, Mar 29, 1957
+Christopher Lee, May 27, 1922
+Christopher Lloyd, Oct 22, 1938
+Christopher Pine, Aug 3, 1976
+Christopher Plummer, Dec 13, 1927
+Christopher Walken, Mar 31, 1943
+The King of Spain, Jan 5, 1938
diff --git a/ch12-new-classes-of-objects/birthday_helper.rb b/ch12-new-classes-of-objects/birthday_helper.rb
index 801de24bd..072da5915 100644
--- a/ch12-new-classes-of-objects/birthday_helper.rb
+++ b/ch12-new-classes-of-objects/birthday_helper.rb
@@ -1 +1,26 @@
-# your code here
\ No newline at end of file
+birth_dates = {}
+
+File.read('birthdates.txt').each_line do |line|
+
+  line = line.chomp
+  first_comma = 0
+
+  while line[first_comma] != ',' && first_comma < line.length
+    first_comma += 1
+  end
+
+  name = line[0..(first_comma - 1)]
+  date = line[-12..-1]
+
+  birth_dates[name] = date
+end
+
+puts "Whose birthday would you like to know?"
+name = gets.chomp
+date = birth_dates[name]
+
+if date == nil
+  puts "Oooh, I don't know that one..."
+else
+  puts date[0..5]
+end
diff --git a/ch12-new-classes-of-objects/happy_birthday.rb b/ch12-new-classes-of-objects/happy_birthday.rb
index 801de24bd..d1ec42a39 100644
--- a/ch12-new-classes-of-objects/happy_birthday.rb
+++ b/ch12-new-classes-of-objects/happy_birthday.rb
@@ -1 +1,20 @@
-# your code here
\ No newline at end of file
+puts "What year were you born in?"
+year = gets.chomp
+
+puts "What month were you born in? (write as a number please)"
+month = gets.chomp
+
+puts "What day were you born?"
+day = gets.chomp
+
+birthday = Time.gm(year, month, day)
+
+puts "Your birthday is " + birthday.to_s
+
+years_alive = ((Time.new - birthday) / 31536000).to_i
+
+puts "Here, have a spank for the #{years_alive} years you've been alive!"
+
+years_alive.times do
+  puts "SPANK!"
+end
diff --git a/ch12-new-classes-of-objects/one_billion_seconds.rb b/ch12-new-classes-of-objects/one_billion_seconds.rb
index 801de24bd..8f646ab12 100644
--- a/ch12-new-classes-of-objects/one_billion_seconds.rb
+++ b/ch12-new-classes-of-objects/one_billion_seconds.rb
@@ -1 +1,4 @@
-# your code here
\ No newline at end of file
+# Figure out what second I was born
+# Calculate my one billionth second birthday
+
+puts Time.gm(1979, 5, 11, 02, 01) + 1000000000
diff --git a/ch12-new-classes-of-objects/party_like_its_roman_to_integer_mcmxcix.rb b/ch12-new-classes-of-objects/party_like_its_roman_to_integer_mcmxcix.rb
index 037b6cb09..7727edcae 100644
--- a/ch12-new-classes-of-objects/party_like_its_roman_to_integer_mcmxcix.rb
+++ b/ch12-new-classes-of-objects/party_like_its_roman_to_integer_mcmxcix.rb
@@ -1,3 +1,31 @@
 def roman_to_integer roman
-  # your code here
-end
\ No newline at end of file
+  # Reject strings which are not valid Roman numerals
+
+  digit_vals = {"i" => 1, "v" => 5, "x" => 10, "l" => 50, "c" => 100, "d" => 500, "m" => 1000}
+
+  total = 0
+  prev = 0
+  index = roman.length - 1
+
+  while index >= 0
+    c = roman[index].downcase
+    index = index - 1
+    val = digit_vals[c]
+    if !val
+      puts "This is not a valid roman numeral"
+      return
+    end
+
+    if val < prev
+      val = val * -1
+    else
+      prev = val
+    end
+    total = total + val
+  end
+
+  total
+end
+
+puts roman_to_integer "mcmxcix"
+puts roman_to_integer "CCCLXV"
diff --git a/ch13-creating-new-classes/extend_built_in_classes.rb b/ch13-creating-new-classes/extend_built_in_classes.rb
index c3e793933..f54484a28 100644
--- a/ch13-creating-new-classes/extend_built_in_classes.rb
+++ b/ch13-creating-new-classes/extend_built_in_classes.rb
@@ -1,3 +1,22 @@
 class Integer
-  # your code here
-end
\ No newline at end of file
+  def factorial
+    if self <=1
+      1
+    else
+      self * (self-1).factorial
+    end
+  end
+
+  def to_roman
+    numberMs = "M" * (self / 1000)
+    numberDs = "D" * ((self % 1000) / 500)
+    numberCs = "C" * ((self % 500) / 100)
+    numberLs = "L" * ((self % 100) / 50)
+    numberXs = "X" * ((self % 50) / 10)
+    numberVs = "V" * ((self % 10) / 5)
+    numberIs = "I" * ((self % 5) / 1)
+
+    return numberMs + numberDs + numberCs + numberLs + numberXs + numberVs + numberIs
+
+  end
+end
diff --git a/ch13-creating-new-classes/interactive_baby_dragon.rb b/ch13-creating-new-classes/interactive_baby_dragon.rb
index 801de24bd..3210a2d91 100644
--- a/ch13-creating-new-classes/interactive_baby_dragon.rb
+++ b/ch13-creating-new-classes/interactive_baby_dragon.rb
@@ -1 +1,142 @@
-# your code here
\ No newline at end of file
+class Dragon
+
+  def initialize name
+    @name = name
+    @asleep = false
+    @stuff_in_belly = 10 # He's full.
+    @stuff_in_intestine = 0 # He doesn't need to go.
+    puts "#{@name} is born."
+    self.ask_for_action
+  end
+
+  def ask_for_action
+    puts
+    puts "What would you like to do with #{@name}? Please type 'feed', 'toss', 'walk', 'put to bed', or 'rock'."
+    action = gets.chomp
+    self.method_dispatch action.downcase
+  end
+
+  def method_dispatch action
+    if action == "feed"
+      self.feed
+    elsif action == "toss"
+      self.toss
+    elsif action == "walk"
+      self.walk
+    elsif action == "put to bed"
+      self.put_to_bed
+    elsif action == "rock"
+      self.rock
+    else
+      puts "I'm sorry. I didn't understand your action."
+      self.ask_for_action
+    end
+  end
+
+  def feed
+    puts "You feed #{@name}."
+    @stuff_in_belly = 10
+    passage_of_time
+  end
+
+  def walk
+    puts "You walk #{@name}."
+    @stuff_in_intestine = 0
+    passage_of_time
+  end
+
+  def put_to_bed
+    puts "You put #{@name} to bed."
+    @asleep = true
+    3.times do
+      if @asleep
+        passage_of_time
+      end
+      if @asleep
+        puts "#{@name} snores, filling the room with smoke."
+      end
+    end
+
+    if @asleep
+      @asleep = false
+      puts "#{@name} wakes up slowly."
+    end
+  end
+
+  def toss
+    puts "You toss #{@name} up into the air."
+    puts 'He giggles, which singes your eyebrows.'
+    passage_of_time
+  end
+
+  def rock
+    puts "You rock #{@name} gently."
+    @asleep = true
+    puts 'He briefly dozes off...'
+    passage_of_time
+    if @asleep
+      @asleep = false
+      puts '...but wakes when you stop.'
+    end
+  end
+
+  private
+
+  # "private" means that the methods defined here are
+  # methods internal to the object. (You can feed your
+  # dragon, but you can't ask him whether he's hungry.)
+
+  def hungry?
+
+  # Method names can end with "?".
+  # Usually, we do this only if the method
+  # returns true or false, like this:
+    @stuff_in_belly <= 2
+  end
+
+  def poopy?
+    @stuff_in_intestine >= 8
+  end
+
+  def passage_of_time
+
+    if @stuff_in_belly > 0
+      # Move food from belly to intestine.
+      @stuff_in_belly = @stuff_in_belly - 1
+      @stuff_in_intestine = @stuff_in_intestine + 1
+    else # Our dragon is starving!
+    if @asleep
+      @asleep = false
+      puts 'He wakes up suddenly!'
+    end
+    puts "#{@name} is starving! In desperation, he ate YOU!"
+    exit # This quits the program.
+    end
+
+    if @stuff_in_intestine >= 10
+      @stuff_in_intestine = 0
+      puts "Whoops! #{@name} had an accident..."
+    end
+
+    if hungry?
+      if @asleep
+        @asleep = false
+        puts 'He wakes up suddenly!'
+      end
+      puts "#{@name}'s stomach grumbles..."
+    end
+
+    if poopy?
+      if @asleep
+        @asleep = false
+        puts 'He wakes up suddenly!'
+      end
+      puts "#{@name} does the potty dance..."
+    end
+
+    self.ask_for_action
+  end
+
+end
+
+pet = Dragon.new 'Norbert'
diff --git a/ch13-creating-new-classes/orange_tree.rb b/ch13-creating-new-classes/orange_tree.rb
index 025d08907..a95f7a6f9 100644
--- a/ch13-creating-new-classes/orange_tree.rb
+++ b/ch13-creating-new-classes/orange_tree.rb
@@ -4,8 +4,134 @@
 # starting in its sixth year have it produce oranges at a rate of (height * 15 - 25) per year.
 # have the tree die after 25 years.
 # check out the rspec spec/ch13/orange_tree_spec.rb to see what strings we're looking for in the responses.
+=begin
+class OrangeTree
+
+  def initialize
+    @height = 0
+    @orange_count = 0
+    @alive = true
+  end
+
+  def height
+    if @alive
+      @height.round(1)
+    else
+      'A dead tree is not very tall. :('
+    end
+  end
+
+  def count_the_oranges
+    if @alive
+      @orange_count
+    else
+      'A dead tree has no oranges. :('
+    end
+  end
+
+  def one_year_passes
+    if @alive
+      @height = @height + 0.4
+      @orange_count = 0 # old oranges fall off
+      if @height > 10.1
+        # tree dies
+        @alive = false
+        'Oh, no! The tree is too old, and has died. :('
+      elsif @height > 2
+        # new oranges grow
+        @orange_count = (@height * 15 - 25).to_i
+        "This year your tree grew to #{@height.round(1)}m tall, and produced #{@orange_count} oranges."
+      else
+        "This year your tree grew to #{@height.round(1)}m tall, but is still too young to bear fruit."
+      end
+    else
+      'A year later, the tree is still dead. :('
+    end
+  end
+
+  def pick_an_orange
+    if @alive
+      if @orange_count > 0
+        @orange_count = @orange_count - 1
+        'You pick a juicy, delicious orange!'
+      else
+        'You search every branch, but find no oranges.'
+      end
+    else
+      'A dead tree has nothing to pick. :('
+    end
+   end
+  end
+=end
+=begin
+tree = OrangeTree.new
+23.times do
+  tree.one_year_passes
+end
+
+tree.one_year_passes
+tree.count_the_oranges
+tree.height
+
+5.times do
+  tree.one_year_passes
+end
+
+tree.height
+tree.count_the_oranges
+tree.pick_an_orange
+=end
 
 
 class OrangeTree
-  # your code here
+
+  def initialize
+    @age = 0
+    @height = 0
+    @growth_rate = 0.4
+    @age_first_fruit = 6
+    @age_of_death = 26
+    @orange_count = 0
+    @alive = true
+  end
+
+  def height
+    if @alive == false
+      "A dead tree is not very tall. :("
+    else
+      @height
+    end
+  end
+
+  def one_year_passes
+    @age += 1
+    if @age < @age_of_death
+      @height = (@age * @growth_rate).round(2)
+      "This year your tree grew to #{self.height}m tall, and produced #{self.count_the_oranges} oranges."
+    elsif @age == @age_of_death
+      @alive = false
+      "Oh, no! The tree is too old, and has died. :("
+    elsif @age > @age_of_death
+      "A year later, the tree is still dead. :("
+    end
+  end
+
+  def count_the_oranges
+    if @age < @age_first_fruit
+      @orange_count
+    elsif @alive == false
+      "A dead tree has no oranges. :("
+    else
+      @orange_count = (@height * 15 - 25).to_i
+    end
+  end
+
+  def pick_an_orange
+    if @alive == false
+      "A dead tree has nothing to pick. :("
+    elsif @orange_count > 0
+      @orange_count -= 1
+    end
+  end
+
 end
diff --git a/ch14-blocks-and-procs/better_program_logger.rb b/ch14-blocks-and-procs/better_program_logger.rb
index 0e2e18d57..896bf8eb2 100644
--- a/ch14-blocks-and-procs/better_program_logger.rb
+++ b/ch14-blocks-and-procs/better_program_logger.rb
@@ -1,3 +1,24 @@
-def log desc, &block
-  # your code here
-end
\ No newline at end of file
+$logger_depth = 0
+
+def better_log desc, &block
+  prefix = ' '*$logger_depth
+  puts prefix+"Beginning #{desc.inspect}..."
+  $logger_depth += 1
+  result = block[]
+  $logger_depth -= 1
+  puts prefix+"...#{desc.inspect} finished, returning: #{result}"
+end
+
+better_log 'outer block' do
+  better_log 'some little block' do
+    better_log 'teeny-tiny block' do
+      'lOtS oF lOVe'.downcase
+    end
+    7 * 3 * 2
+  end
+
+  better_log 'yet another block' do
+    '!doof naidnI evol I'.reverse
+  end
+  '0' == "0"
+end
diff --git a/ch14-blocks-and-procs/even_better_profiling.rb b/ch14-blocks-and-procs/even_better_profiling.rb
index b01b78fd8..ee7873792 100644
--- a/ch14-blocks-and-procs/even_better_profiling.rb
+++ b/ch14-blocks-and-procs/even_better_profiling.rb
@@ -1,3 +1,30 @@
 def profile block_description, &block
-  # your code here
-end
\ No newline at end of file
+
+  profiling_on = true
+
+  if profiling_on
+    start_time = Time.new
+    block.call
+    duration = Time.new - start_time
+    puts "#{block_description}: #{duration} seconds"
+  else
+    block.call
+  end
+
+end
+
+profile '25000 doublings' do
+  number = 1
+  25000.times do
+    number = number + number
+  end
+  puts "#{number.to_s.length} digits"
+  # That's the number of digits in this HUGE number.
+end
+
+profile 'count to a million' do
+  number = 0
+  1000000.times do
+    number = number + 1
+  end
+end
diff --git a/ch14-blocks-and-procs/grandfather_clock.rb b/ch14-blocks-and-procs/grandfather_clock.rb
index 916f6d354..a8323b464 100644
--- a/ch14-blocks-and-procs/grandfather_clock.rb
+++ b/ch14-blocks-and-procs/grandfather_clock.rb
@@ -1,3 +1,19 @@
 def grandfather_clock &block
-  # your code here
-end
\ No newline at end of file
+  hour = Time.new.hour
+
+  if hour >= 13
+    hour -= 12
+  end
+
+  if hour == 0
+    hour = 12
+  end
+
+  hour.times do
+    block.call
+  end
+end
+
+grandfather_clock do
+  puts "DONG!"
+end
diff --git a/ch14-blocks-and-procs/program_logger.rb b/ch14-blocks-and-procs/program_logger.rb
index 0e2e18d57..3438199fb 100644
--- a/ch14-blocks-and-procs/program_logger.rb
+++ b/ch14-blocks-and-procs/program_logger.rb
@@ -1,3 +1,17 @@
-def log desc, &block
-  # your code here
-end
\ No newline at end of file
+def program_log desc, &block
+  puts 'Beginning "' + desc + '"...'
+  result = block.call
+  puts '..."' + desc + '" finished, returning: ' + result.to_s
+end
+
+program_log 'outer block' do
+  program_log 'some little block' do
+    1**1 + 2**2
+  end
+
+  program_log 'yet another block' do
+    '!doof iahT ekil I'.reverse
+  end
+
+  '0' == 0
+end