diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..06b0c5b42
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,7 @@
+def greet(name)
+  return "Hello, #{name}!"
+end
+
+def hello
+  return "Hello!"
+end
\ No newline at end of file
diff --git a/01_temperature/temperature.rb b/01_temperature/temperature.rb
new file mode 100644
index 000000000..003b02731
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,9 @@
+def ftoc(fahrenheit)
+  celsius = (fahrenheit-32)*5/9
+  return celsius
+end
+
+def ctof(celsius)
+  fahrenheit = (celsius*9.0/5.0)+32
+  return fahrenheit
+end
\ No newline at end of file
diff --git a/02_calculator/calculator.rb b/02_calculator/calculator.rb
new file mode 100644
index 000000000..d2da6ae22
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,19 @@
+def add(num1, num2)
+  sum = num1 + num2
+  return sum
+end
+
+def subtract(num1, num2)
+  difference = num1 - num2
+  return difference
+end
+
+def sum(arr)
+  total = 0
+  arr.each{|x| total += x }
+  return total
+end
+
+def multiply
+
+end
diff --git a/03_simon_says/simon_says.rb b/03_simon_says/simon_says.rb
new file mode 100644
index 000000000..d0fb33f07
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,42 @@
+def echo(str)
+  return str
+end
+
+def shout(str)
+  return str.upcase
+end
+
+def repeat(str, n=2)
+#  array where each element is str and there are n of them.
+  arr = []
+  n.times{arr.push(str)}
+  return arr.join(" ")
+#  then i can join them with a space and return that
+ # return str+" "+str
+end
+
+def start_of_word(word, int)
+  word[0..(int-1)]
+end
+
+def first_word(str)
+  arr = str.split(" ")
+  return arr[0]
+end
+
+def titleize(str)
+  little_words = ['and', 'the', 'over']
+  arr = str.split(" ")
+  upcase_array = []
+  i = 0
+  arr.each do |word|
+    i += 1 
+    if little_words.include?(word) && i != 1
+      upcase_array.push(word)
+    else  
+      upcase_array.push(word.capitalize)
+    end
+  end
+  new_str = upcase_array.join(" ")
+
+end
\ No newline at end of file
diff --git a/04_pig_latin/pig_latin.rb b/04_pig_latin/pig_latin.rb
new file mode 100644
index 000000000..c6058c945
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,23 @@
+def translate(word)
+  vowels = ['a','e','i','o','u']
+
+  pre_latin = word.split(" ")
+
+  arr=[]
+
+  pre_latin.each do |piggy|
+
+    if vowels.include?(piggy[0])
+      arr.push(piggy + "ay")
+    elsif piggy[0..1] == "qu"
+      arr.push(piggy[2..(piggy.length-1)] + piggy[0..1] + "ay")
+    elsif vowels.include?(piggy[1])
+      arr.push(piggy[1..(piggy.length-1)] + piggy[0] + "ay")
+    elsif vowels.include?(piggy[2])
+      arr.push(piggy[2..(piggy.length-1)] + piggy[0..1] + "ay")
+    else
+      arr.push(piggy[3..(piggy.length-1)] + piggy[0..2] + "ay")
+    end
+  end
+  latinized = arr.join(" ")
+end
\ No newline at end of file
diff --git a/05_silly_blocks/silly_blocks.rb b/05_silly_blocks/silly_blocks.rb
new file mode 100644
index 000000000..6064bab7e
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,14 @@
+def reverser
+  reversed = yield.split(" ").map{|word| word.reverse}
+  return reversed.join(" ")
+end
+
+def adder(n=1)
+  yield + n
+end
+
+def repeater(n=1)
+  block_was_executed = false
+  n.times { yield }
+  block_was_executed = true
+end
\ No newline at end of file
diff --git a/06_performance_monitor/performance_monitor.rb b/06_performance_monitor/performance_monitor.rb
new file mode 100644
index 000000000..61b4c1b37
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,5 @@
+def measure(n=1)
+  start_time = Time.now
+  n.times{ yield }
+  elapsed_time = (Time.now - start_time)/n
+end
\ No newline at end of file
diff --git a/07_hello_friend/friend.rb b/07_hello_friend/friend.rb
new file mode 100644
index 000000000..805b7da3b
--- /dev/null
+++ b/07_hello_friend/friend.rb
@@ -0,0 +1,9 @@
+class Friend
+  def greeting(name=nil)
+    if name != nil
+      "Hello, #{name}!"
+    else
+      "Hello!"
+    end
+  end
+end
\ No newline at end of file
diff --git a/08_book_titles/book.rb b/08_book_titles/book.rb
new file mode 100644
index 000000000..84280e4db
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,21 @@
+class Book
+
+  def title=(title)
+    no_nos = ['and','in','the','of','a','an']
+    i = 0
+
+    @title = title.split(" ").map! do |word|
+      i+=1
+      if !no_nos.include?(word) || i == 1
+        word.capitalize
+      else
+        word
+      end
+    end.join(" ")
+  end
+
+  def title
+    @title
+  end
+
+end
\ No newline at end of file
diff --git a/09_timer/timer.rb b/09_timer/timer.rb
new file mode 100644
index 000000000..493540853
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,20 @@
+class Timer
+  
+  def initialize
+    self.seconds = (0)
+  end
+
+  def seconds=(seconds)
+    @seconds = seconds
+    @time_string = Time.at(seconds).utc.strftime("%H:%M:%S")
+  end
+
+  def seconds
+    @seconds
+  end
+
+  def time_string
+    @time_string
+  end
+
+end
\ No newline at end of file
diff --git a/10_temperature_object/temperature.rb b/10_temperature_object/temperature.rb
new file mode 100644
index 000000000..ed3e78154
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,49 @@
+class Temperature
+  attr_accessor :f, :c
+
+  def Temperature.from_celsius temp
+    Temperature.new(:c => temp)
+  end
+
+  def Temperature.from_fahrenheit temp
+    Temperature.new(:f => temp)
+  end
+  
+  def initialize args
+    @f = args[:f]
+    @c = args[:c]
+    if @f 
+      @c = ftoc
+    else
+      @f = ctof
+    end
+  end
+
+  def ftoc
+    (@f-32)*5/9.0
+  end
+
+  def ctof
+    (@c*9/5.0)+32
+  end
+
+  def in_fahrenheit
+    @f
+  end
+
+  def in_celsius
+    @c
+  end
+end
+
+class Celsius < Temperature
+  def Celsius.new args
+    Temperature.new(:c => 50)
+  end
+end
+
+class Fahrenheit < Temperature
+  def Fahrenheit.new args
+    Temperature.new(:f => 50)
+  end
+end
\ No newline at end of file
diff --git a/11_dictionary/dictionary.rb b/11_dictionary/dictionary.rb
new file mode 100644
index 000000000..8fc1cf25a
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,38 @@
+class Dictionary
+
+  attr_reader :entries
+
+  def initialize
+    @entries = {}
+  end
+
+  def add items
+    if items.is_a?(Hash)
+      items.each {|key, definition| @entries[key] = definition}
+    else
+      @entries[items] = nil
+    end
+    @entries = Hash[@entries.sort_by {|key, definition| key}]
+  end
+
+  def find partial
+    @entries.select {|key, definition| key.include? partial}
+  end
+
+  def include? key
+    @entries.has_key? key
+  end
+
+  def keywords
+    @entries.keys
+  end
+
+  def printable
+    output = ""
+    @entries.each do |key, definition|
+      output += "[#{key}] \"#{definition}\"\n"
+    end
+    output.chomp
+  end
+
+end
\ No newline at end of file
diff --git a/12_rpn_calculator/rpn_calculator.rb b/12_rpn_calculator/rpn_calculator.rb
new file mode 100644
index 000000000..137c28906
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,49 @@
+class RPNCalculator
+  
+  attr_reader :value
+
+  def initialize
+    @value = 0
+    @entered = []
+  end
+
+  def divide
+    operate &:/
+  end
+
+  def evaluate formula
+    formula = tokens formula
+    formula.each do |token|
+      (token.class == Symbol ? operate(&token) : push(token))
+    end
+    return @value
+  end
+
+  def minus
+    operate &:-
+  end
+
+  def operate &operator
+    raise "calculator is empty" if @entered.length < 2
+    @value = @entered.push(@entered.pop(2).reduce &operator)[-1]
+  end
+
+  def plus
+    operate &:+
+  end
+
+  def push num
+    @entered << num.to_f
+  end
+
+  def times
+    operate &:*
+  end
+
+  def tokens token_list
+    token_list.split(" ").map do |token| 
+      (token.to_i.to_s == token ? token.to_i : token.to_sym)
+    end
+  end
+
+end
\ No newline at end of file
diff --git a/13_xml_document/xml_document.rb b/13_xml_document/xml_document.rb
new file mode 100644
index 000000000..3e38ee13e
--- /dev/null
+++ b/13_xml_document/xml_document.rb
@@ -0,0 +1,5 @@
+class XmlDocument
+
+  def hello
+  end
+end
\ No newline at end of file
diff --git a/14_array_extensions/array_extensions.rb b/14_array_extensions/array_extensions.rb
new file mode 100644
index 000000000..aaac07cc3
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,24 @@
+class Array
+
+  def sum
+    result = 0
+    self.each do |i|
+      result += i
+    end
+    result
+  end
+
+  def square
+    result = []
+    self.map do |i|
+      result << i * i
+    end
+    result
+  end
+
+  def square!
+    self.map! do |i|
+      i * i
+    end
+  end
+end
\ No newline at end of file
diff --git a/15_in_words/in_words.rb b/15_in_words/in_words.rb
new file mode 100644
index 000000000..8502f404a
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,68 @@
+class Fixnum
+  def in_words
+    case  
+    when self >= 1_000_000_000_000 then hundreds_and_up(1_000_000_000_000)
+    when self >= 1_000_000_000 then hundreds_and_up(1_000_000_000)
+    when self >= 1_000_000 then hundreds_and_up(1_000_000)
+    when self >= 1000 then hundreds_and_up(1_000)
+    when self >= 100 then hundreds_and_up(100)
+    when self/10 > 1 #tens
+      return tens(self/10) if self%10 == 0 
+      return tens(self/10) + " " + singles(self%10)
+    when self/10 == 1 # teens 
+      return 'ten' if self == 10
+      return 'eleven' if self == 11
+      return 'twelve' if self == 12 
+      return teen_beginnings(self%10) + 'teen'
+    when self/10 == 0
+      return singles(self)
+    else 
+      return "Sorry, too high!"
+    end 
+  end
+
+  def descriptor(place)
+    return " trillion" if place == 1_000_000_000_000
+    return " billion" if place == 1_000_000_000
+    return " million" if place == 1_000_000
+    return " thousand" if place == 1000
+    return " hundred"
+  end
+
+  def hundreds_and_up(place)
+    return (self/place).in_words + descriptor(place) if self%place == 0
+    return (self/place).in_words + descriptor(place) + " " + (self%place).in_words
+  end
+
+  def singles(n)
+    return 'zero' if n == 0
+    return 'one' if n == 1
+    return 'two' if n == 2 
+    return 'three' if n == 3
+    return 'four' if n == 4
+    return 'five' if n == 5
+    return 'six' if n == 6
+    return 'seven' if n == 7 
+    return 'eight' if n == 8
+    return 'nine' if n == 9
+  end
+
+  def teen_beginnings(n)
+    return 'thir' if n == 3
+    return 'four' if n == 4
+    return 'fif' if n == 5
+    return 'eigh' if n == 8
+    return singles(n)
+  end
+
+  def tens(n)
+    return 'twenty' if n == 2 
+    return 'thirty' if n == 3
+    return 'forty' if n == 4
+    return 'fifty' if n == 5
+    return 'sixty' if n == 6
+    return 'seventy' if n == 7 
+    return 'eighty' if n == 8
+    return 'ninety' if n == 9
+  end
+end
\ No newline at end of file