diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..3623e57f4
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(who)
+  "Hello, #{who}!"
+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..227923755
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,7 @@
+def ftoc(f)
+  (f - 32) * 5.0 / 9.0
+end
+
+def ctof(c)
+  (c * 9.0 / 5.0) +32
+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..2e87ab7dd
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,31 @@
+def add(a,b)
+  a+b
+end
+
+def subtract(a,b)
+  a-b
+end
+
+def sum(arr)
+  total = 0
+  arr.each do |num|
+    total += num
+  end
+  total
+end
+
+def multiply(*args)
+  total = 1
+  args.each do |num|
+    total *= num
+  end
+  total
+end
+
+def power(a,b)
+  a**b
+end
+
+def factorial(num)
+  (1..num).inject(:*) || 1
+end
\ No newline at end of file
diff --git a/02_calculator/calculator_spec.rb b/02_calculator/calculator_spec.rb
index fef7e9d00..012d616b7 100644
--- a/02_calculator/calculator_spec.rb
+++ b/02_calculator/calculator_spec.rb
@@ -77,23 +77,38 @@
 # once the above tests pass,
 # write tests and code for the following:
 
-describe "#multiply" do
+describe "multiply" do
 
-  it "multiplies two numbers"
+  it "multiplies two numbers" do
+    expect(multiply(2,3)).to eq(6)
+  end
 
-  it "multiplies several numbers"
-  
+  it "multiplies several numbers" do
+    expect(multiply(2,3,4)).to eq(24)
+  end
 end
 
-describe "#power" do
-  it "raises one number to the power of another number"
+describe "power" do
+  it "raises one number to the power of another number" do
+    expect(power(3,4)).to eq(81)
+  end
 end
 
 # http://en.wikipedia.org/wiki/Factorial
-describe "#factorial" do
-  it "computes the factorial of 0"
-  it "computes the factorial of 1"
-  it "computes the factorial of 2"
-  it "computes the factorial of 5"
-  it "computes the factorial of 10"
+describe "factorial" do
+  it "computes the factorial of 0" do
+    expect(factorial(0)).to eq(1)
+  end
+  it "computes the factorial of 1" do
+    expect(factorial(1)).to eq(1)
+  end
+  it "computes the factorial of 2" do
+    expect(factorial(2)).to eq(2)
+  end
+  it "computes the factorial of 5" do
+    expect(factorial(5)).to eq(120)
+  end
+  it "computes the factorial of 10" do
+    expect(factorial(10)).to eq(3628800)
+  end
 end
diff --git a/03_simon_says/simon_says.rb b/03_simon_says/simon_says.rb
new file mode 100644
index 000000000..1536b58c6
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,40 @@
+def echo(word)
+  word
+end
+
+def shout(word)
+  word.upcase
+end
+
+def repeat(word, cycles=2)
+  total = word
+  (cycles - 1).times do
+    total += " " + word
+  end
+  total
+end
+
+def start_of_word(word, num)
+  word[0..(num - 1)]
+end
+
+def first_word(phrase)
+  arr = phrase.split(" ")
+  arr[0]
+end
+
+def titleize(phrase)
+  little_words = ["and", "over", "the"]
+  arr = phrase.split(" ")
+  return_string = arr.shift.capitalize
+  arr.each do |word|
+    if little_words.include?(word)
+      add_word = word
+    else
+      add_word = word.capitalize
+    end
+    # add_word = word.capitalize unless little_words.include?(word)
+    return_string += " " + add_word
+  end
+  return_string
+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..64344e940
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,27 @@
+def translate(words)
+  def translate_word(word)
+    def move_first_to_last(starts_w_cons)
+      move_front = starts_w_cons[0]
+      starts_w_cons[0] = ""
+      if move_front == "q"
+        move_front += "u"
+        starts_w_cons[0] = ""
+      end
+      starts_w_cons + move_front
+    end
+    vowels = ["a", "e", "i", "o", "u", "y"]
+
+    until vowels.include?(word[0])
+      word = move_first_to_last(word)
+    end
+
+    word + "ay"
+  end
+
+  words_array = words.split(" ")
+  return_string = ""
+  words_array.each do |w|
+    return_string += translate_word(w) + " "
+  end
+  return_string.strip
+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..1d9549213
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,33 @@
+# def reverser(&block)
+#   block.each do |b|
+#     call.reverse
+#   end
+# end
+
+# def reverser
+#   yield.reverse
+# end
+
+# def reverser(&block)
+#   block.call.reverse
+# end
+
+
+def reverser
+  arr = yield.split(" ")
+  return_string = ""
+  arr.each do |word|
+    return_string += word.reverse + " "
+  end
+  return_string.strip
+end
+
+def adder(increase=1)
+  yield + increase
+end
+
+def repeater(multiplier = 1)
+  multiplier.times do
+    yield
+  end
+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..f72ec9cf9
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,10 @@
+def measure(cycles = 1)
+  counts = 0
+  cycles.times do
+    start_time = Time.now
+    yield
+    end_time = Time.now
+    counts += (elapsed_time = end_time - start_time)
+  end
+  counts.to_f/cycles.to_f
+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..102d5ae25
--- /dev/null
+++ b/07_hello_friend/friend.rb
@@ -0,0 +1,9 @@
+class Friend
+  def greeting(who = nil)
+    if who.nil?
+      "Hello!"
+    else
+      "Hello, #{who}!"
+    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..7c41f1ed1
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,27 @@
+class Book
+  def title
+    @title
+  end
+
+  def title=(title)
+    @title = titlieze(title)
+  end
+
+  private
+  def titlieze(title)
+    little_words = ["the", "a", "in", "of", "and", "an"]
+    arr = title.split(" ")
+    return_string = arr.shift.capitalize
+
+    arr.each do |word|
+      if little_words.include?(word)
+        add_word = word
+      else
+        add_word = word.capitalize
+      end
+      return_string += " " + add_word
+    end
+    return_string
+  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..4013a3bc3
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,26 @@
+class Timer
+  attr_accessor :seconds
+  def initialize
+    @seconds = 0
+  end
+
+  def time_string
+    "#{padded(hours)}:#{padded(minutes)}:#{padded(remainder_seconds)}"
+  end
+
+  def hours
+    seconds / 3600
+  end
+
+  def minutes
+    (seconds % 3600)/60
+  end
+
+  def remainder_seconds
+    (seconds % 60)
+  end
+
+  def padded(number)
+    "#{number}".rjust(2, '0')
+  end
+end
\ No newline at end of file
diff --git a/09_timer/timer_spec.rb b/09_timer/timer_spec.rb
index 40b33f23f..b998bf1b2 100644
--- a/09_timer/timer_spec.rb
+++ b/09_timer/timer_spec.rb
@@ -44,17 +44,17 @@
   # One way to implement the Timer is with a helper method.
   # Uncomment these specs if you want to test-drive that
   # method, then call that method from inside of time_string.
-  #
-  # describe 'padded' do
-  #   it 'pads zero' do
-  #     expect(@timer.padded(0)).to eq('00')
-  #   end
-  #   it 'pads one' do
-  #     expect(@timer.padded(1)).to eq('01')
-  #   end
-  #   it "doesn't pad a two-digit number" do
-  #     expect(@timer.padded(12)).to eq('12')
-  #   end
-  # end
+  
+  describe 'padded' do
+    it 'pads zero' do
+      expect(@timer.padded(0)).to eq('00')
+    end
+    it 'pads one' do
+      expect(@timer.padded(1)).to eq('01')
+    end
+    it "doesn't pad a two-digit number" do
+      expect(@timer.padded(12)).to eq('12')
+    end
+  end
 
 end
diff --git a/10_temperature_object/temperature.rb b/10_temperature_object/temperature.rb
new file mode 100644
index 000000000..761b064dc
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,40 @@
+class Temperature
+  def initialize(temp_hash)
+    @f = temp_hash[:f]
+    @c = temp_hash[:c]
+  end
+
+  def in_fahrenheit
+    @f              ||
+    (@c * 9.0 / 5.0) +32
+  end
+
+  def in_celsius
+    @c              ||
+    (@f - 32) * 5.0 / 9.0
+  end
+
+
+  class << self
+    def from_fahrenheit temp
+      Temperature.new({f: temp})
+    end
+
+    def from_celsius temp
+      Temperature.new({c: temp})
+    end
+  end
+end
+
+
+class Celsius < Temperature
+  def initialize temp
+    super(c: temp)
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize(temp)
+    super(f: temp)
+  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..f02315928
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,34 @@
+class Dictionary
+  def initialize(defs = {})
+    @defs = defs
+  end
+
+  def entries
+   @defs
+  end
+
+  def add(defs)
+    if defs.is_a?(String)
+        @defs.merge!(defs => nil)
+    else
+        @defs.merge!(defs)
+    end
+  end
+
+  def keywords
+    @defs.keys.sort
+  end
+
+  def include?(key)
+    @defs.has_key?(key)
+  end
+
+  def find(key)
+    @defs.select { |word,defin| word.scan(key).join == key }
+  end
+
+  def printable
+    defs_sorted = @defs.sort_by { |word, defin| word}
+    defs_sorted.map{ |word, defin| "[#{word}] \"#{defin}\"\n" }.join.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..190bb5162
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,98 @@
+class RPNCalculator
+
+  def initialize(num = 0, arr = [])
+    @num = num
+    @arr = arr
+  end
+
+  def push(num)
+    @arr << num
+  end
+
+  def plus
+    if @arr.length == 0
+      raise("calculator is empty")
+    elsif @arr.length > 1
+      @num += @arr.pop + @arr.pop
+    else
+      @num += @arr.pop
+    end
+  end
+
+  def value
+    @num
+  end
+
+  def minus
+    if @arr.length == 0
+      raise("calculator is empty")
+    elsif @arr.length > 1
+      @num -= @arr.pop
+      @num += @arr.pop
+    else
+      @num -= @arr.pop
+    end
+  end
+
+  def divide
+    if @arr.length == 0
+      raise("calculator is empty")
+    elsif @arr.length > 1
+      @num += (@arr[-2] / @arr.pop.to_f)
+      @arr.pop
+    else
+      @num /= @arr.pop.to_f
+    end
+  end
+
+  def times
+    if @arr.length == 0
+      raise("calculator is empty")
+    elsif @arr.length > 1
+      @num += @arr.pop * @arr.pop
+    else
+      @num *= @arr.pop
+    end
+  end
+
+  def tokens(string)
+    arr = string.split(" ")
+    symbols = ["+", "-", "/", "*"]
+    arr.collect! do |char|
+      if symbols.include?(char)
+        char.to_sym
+      else
+        char.to_i
+      end
+    end
+    arr
+  end
+
+  def evaluate(string)
+    tokens(string).each do |sym|
+      # if sym == :+
+      #   self.plus
+      # elsif sym == :-
+      #   self.minus
+      # elsif sym == :/
+      #   self.divide
+      # elsif sym == :*
+      #   self.times
+      # else
+      #   push(sym.to_f)
+      if sym == :-
+        self.minus
+      elsif sym == :+
+        self.plus
+      elsif sym == :/
+        self.divide
+      elsif sym == :*
+        self.times
+      else
+        push(sym.to_f)
+      end
+    end
+    self.value
+  end
+
+end
diff --git a/12_rpn_calculator/rpn_calculator_spec.rb b/12_rpn_calculator/rpn_calculator_spec.rb
index a79d0a369..191e19d7c 100644
--- a/12_rpn_calculator/rpn_calculator_spec.rb
+++ b/12_rpn_calculator/rpn_calculator_spec.rb
@@ -97,6 +97,7 @@
     expect(calculator.value).to eq((1+2)*3)
 
     # 1 2 3 * + => 1 + (2 * 3)
+    @calculator = RPNCalculator.new #I added this
     calculator.push(1)
     calculator.push(2)
     calculator.push(3)
@@ -131,11 +132,11 @@
   # extra credit
   it "evaluates a string" do
     expect(calculator.evaluate("1 2 3 * +")).to eq((2 * 3) + 1)
-
+    @calculator = RPNCalculator.new #I added this
     expect(calculator.evaluate("4 5 -")).to eq(4 - 5)
-
+    @calculator = RPNCalculator.new #I added this
     expect(calculator.evaluate("2 3 /")).to eq(2.0 / 3.0)
-
+    @calculator = RPNCalculator.new #I added this
     expect(calculator.evaluate("1 2 3 * + 4 5 - /")).to eq( (1.0 + (2 * 3)) / (4 - 5) )
   end
 
diff --git a/14_array_extensions/array_extensions.rb b/14_array_extensions/array_extensions.rb
new file mode 100644
index 000000000..baa1b9ab4
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,28 @@
+class Array
+  def sum
+    if self.length == 0
+      0
+    else
+      self.inject(0){|sum,x| sum + x }
+    end
+  end
+
+  def square
+    if self.empty?
+      []
+    else
+      self.map { |e| e**2 }
+    end
+  end
+
+  def square!
+    if self.empty?
+      []
+    else
+      self.map! { |e| e**2 }
+    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..5713b237a
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,65 @@
+class Fixnum
+  def in_words
+    below_13={0 => 'zero', 1 => 'one', 2 => 'two', 3 => 'three', 4 => 'four', 5 => 'five', 6 => 'six', 7=> 'seven', 8 => 'eight', 9 => 'nine', 10 => 'ten', 11 => 'eleven', 12 => 'twelve', 13 => 'thirteen'}
+    tens={20 => 'twenty', 30 => 'thirty', 40 => 'forty', 50 => 'fifty', 60 => 'sixty', 70 => 'seventy', 80 => 'eighty', 90 => 'ninety'}
+    case self
+    when 0..13
+      below_13[self]
+    when 14, 16, 17, 19
+      teen
+    when 15
+      'fifteen'
+    when 18
+      'eighteen'
+    when 20, 30, 40, 50 , 60, 70, 80, 90
+      tens[self]
+    when (20..99)
+      tens = (self / 10) * 10
+      ones = self - tens
+      "#{tens.in_words} #{ones.in_words}"
+    when (100..999)
+      hundreds = self / 100
+      rest = self - (hundreds * 100)
+      if rest > 0
+        "#{hundreds.in_words} hundred #{rest.in_words}"
+      else
+        "#{hundreds.in_words} hundred"
+      end
+    when (1_000..999_999)
+      thousands = self / 1_000
+      rest = self - (thousands * 1_000)
+      if rest > 0
+        "#{thousands.in_words} thousand #{rest.in_words}"
+      else
+        "#{thousands.in_words} thousand"
+      end
+    when (1_000_000..999_999_999)
+      millions = self / 1_000_000
+      rest = self - (millions * 1_000_000)
+      if rest > 0
+        "#{millions.in_words} million #{rest.in_words}"
+      else
+        "#{millions.in_words} million"
+      end
+    when (1_000_000_000..999_999_999_999)
+      billions = self / 1_000_000_000
+      rest = self - (billions * 1_000_000_000)
+      if rest > 0
+        "#{billions.in_words} billion #{rest.in_words}"
+      else
+        "#{billions.in_words} billion"
+      end
+    when (1_000_000_000_000..999_999_999_999_999)
+      trillions = self / 1_000_000_000_000
+      rest = self - (trillions * 1_000_000_000_000)
+      if rest > 0
+        "#{trillions.in_words} trillion #{rest.in_words}"
+      else
+        "#{trillions.in_words} trillion"
+      end
+    end
+  end
+  def teen
+    (self - 10).in_words + 'teen'
+  end
+end
diff --git a/Gemfile.lock b/Gemfile.lock
index 1f62661aa..0c36c5796 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -14,7 +14,7 @@ GEM
     pry-byebug (3.2.0)
       byebug (~> 5.0)
       pry (~> 0.10)
-    rake (10.4.2)
+    rake (11.3.0)
     rspec (3.1.0)
       rspec-core (~> 3.1.0)
       rspec-expectations (~> 3.1.0)
@@ -38,4 +38,4 @@ DEPENDENCIES
   rspec (~> 3.0)
 
 BUNDLED WITH
-   1.10.5
+   1.13.2