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..1b5a5fb7b
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,7 @@
+def ftoc(farenheit)
+  celsius = (farenheit - 32) * 5.0/9.0
+end
+
+def ctof(celsius)
+  farenheit = ( celsius * 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..fe98df6f2
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,27 @@
+def add(in1, in2)
+  result = in1 + in2
+end
+
+def subtract(in1, in2)
+  result = in1 - in2
+end
+
+def sum(array_of_ins)
+  out = array_of_ins.inject(0) { |running_total, item| running_total + item }
+end
+
+def multiply(in1, in2)
+  out = in1 * in2
+end
+
+def power(input, to_power)
+  out = input ** to_power
+end
+
+def factorial(input)
+  if input == 0
+    out = 1
+  elsif input > 0
+    out = input * factorial(input - 1)
+  end
+end
\ No newline at end of file
diff --git a/02_calculator/calculator_spec.rb b/02_calculator/calculator_spec.rb
index fef7e9d00..1246d3012 100644
--- a/02_calculator/calculator_spec.rb
+++ b/02_calculator/calculator_spec.rb
@@ -79,21 +79,37 @@
 
 describe "#multiply" do
 
-  it "multiplies two numbers"
+  it "multiplies two numbers" do
+    expect(multiply(5,5)).to eq(25)
+  end
 
-  it "multiplies several numbers"
+  it "multiplies several numbers" do
+    expect(multiply(-2,9)).to eq(-18)
+  end
   
 end
 
 describe "#power" do
-  it "raises one number to the power of another number"
+  it "raises one number to the power of another number" do
+    expect(power(3,3)).to eq(27)
+  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"
+  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..154e16379
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,28 @@
+def echo(input)
+  input
+end
+
+def shout(input)
+  out = input.upcase
+end
+
+def repeat(input, how_many_times=2)
+  out = input + ( " #{input}" * ( how_many_times - 1 ))
+end
+
+def start_of_word(string, index=0)
+  out = string[0..index-1]
+end
+
+def first_word(string)
+  array = string.split(" ")
+  out = array[0]
+end
+
+def titleize(string)
+  array = string.split(" ")
+  array = array.each_with_index { |item, index|
+    item.capitalize! unless item == "and" || ( item == "the" && index != 0 ) || item == "over"
+  }
+  out = 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..3d5704b69
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,30 @@
+def translate(string)
+  array = string.split(" ")
+  vowels = ["a", "e", "i", "o", "u"]
+  double_consonants = ["ch", "tr", "ph", "gr", "br", "gl", "sh", "fr", "bl", "th", "sp", "qu"]
+  triple_consonants = ["thr", "spl", "shr", "chr", "str", "sch", "squ"]
+  array = array.each_with_index do |item, index|
+    if vowels.include?(item[0])
+      item = item << "ay"
+    elsif triple_consonants.include?(item[0..2])
+      item = item << item[0..2] << "ay"
+      item[0..2] = ""
+    elsif double_consonants.include?(item[0..1])
+      item = item << item[0..1] << "ay"
+      item[0..1] = ""
+    elsif item[0] == item[0].upcase
+      item = item << item[0].downcase << "ay"
+      item[1] = item[1].upcase
+      item[0] = ""
+    else
+      item = item << item[0] << "ay"
+      item[0] = ""
+    end
+  end
+  out = array.join(" ")
+  if out[-4] == "."
+    out[-4] = ""
+    out << "."
+  end
+  out
+end
\ No newline at end of file
diff --git a/04_pig_latin/pig_latin_spec.rb b/04_pig_latin/pig_latin_spec.rb
index cc659edfd..18e538348 100644
--- a/04_pig_latin/pig_latin_spec.rb
+++ b/04_pig_latin/pig_latin_spec.rb
@@ -67,6 +67,13 @@
 
   # Test-driving bonus:
   # * write a test asserting that capitalized words are still capitalized (but with a different initial capital letter, of course)
+  it "retains capitalization" do
+    s = translate("Meowing Monkey")
+    expect(s).to eq("Eowingmay Onkeymay")
+  end
   # * retain the punctuation from the original phrase
-
+  it "retains punctuation" do
+    s = translate("You suck.")
+    expect(s).to eq("Ouyay ucksay.")
+  end
 end
diff --git a/05_silly_blocks/silly_blocks.rb b/05_silly_blocks/silly_blocks.rb
new file mode 100644
index 000000000..4ce6c1f92
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,13 @@
+def reverser
+  words = yield.split(" ")
+  words = words.each { |word| word.reverse! }
+  out = words.join(" ")
+end
+
+def adder(how_much=1)
+  out = yield + how_much
+end
+
+def repeater(how_much=1)
+  how_much.times { yield }
+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..027153388
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,5 @@
+def measure(n=1)
+  start = Time.now
+  n.times { yield }
+  out = ( Time.now - start ) / 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..5faf65cb9
--- /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..f9c482504
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,14 @@
+class Book
+  attr_accessor :title
+  def title
+    articles = ["and", "in", "the", "of", "a", "an"]
+    words = @title.split(" ")
+    words = words.each_with_index { |word, index|
+        word.capitalize! unless articles.include? word
+        if index == 0
+          word.capitalize!
+        end
+    }
+    out = words.join(" ")
+  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..931b32b93
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,29 @@
+class Timer
+  attr_accessor :seconds
+  def initialize
+    @seconds = 0
+  end
+  def time_string
+    "#{padded(hours)}:#{padded(minutes)}:#{padded(seconds)}"
+  end
+  def seconds
+    seconds = @seconds % 60
+  end
+  def minutes
+    minutes = ( @seconds - ( hours * 3600 )) / 60
+  end
+  def hours
+    hours = @seconds / 3600
+  end
+  def padded(value)
+    value = value.to_s
+    digits = value.length
+    if digits == 0
+      "00"
+    elsif digits == 1
+      "0" + value
+    else
+      value
+    end
+  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..408efc0d1
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,36 @@
+class Temperature
+  def initialize(opts = {})
+    @fahrenheit, @celsius = opts[:f], opts[:c]
+    if @fahrenheit != nil && @celsius == nil
+      @celsius = ( @fahrenheit - 32 ) * 5.0/9.0
+    elsif @celsius != nil && @fahrenheit == nil
+      @fahrenheit = (@celsius * 9.0/5.0) + 32
+    end
+  end
+  def in_fahrenheit
+    @fahrenheit
+  end
+  def in_celsius
+    @celsius
+  end
+  def self.from_celsius(celsius_value)
+    Temperature.new(c: celsius_value)
+  end
+  def self.from_fahrenheit(fahrenheit_value)
+    Temperature.new(f: fahrenheit_value)
+  end
+end
+
+class Celsius < Temperature
+  def initialize(value)
+    @celsius = value
+    @fahrenheit = ( value * 9.0 / 5.0 ) + 32
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize(value)
+    @fahrenheit = value
+    @celsius = ( value - 32 ) * 5.0/9.0
+  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..8c73194b0
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,36 @@
+class Dictionary
+  def initialize
+    @d = {}
+  end
+  def entries
+    @d
+  end
+  def add(entry)
+    if entry.is_a?(Hash)
+      @d.merge!(entry)
+    elsif entry.is_a?(String)
+      @d[entry] = nil
+    end
+  end
+  def keywords
+    @d.keys.sort!
+  end
+  def include?(entry)
+    @d.keys.include?(entry)
+  end
+  def find(entry)
+    results = {}
+    @d.each { |key, value|
+      if key.start_with?(entry)
+        results[key] = value
+      end
+    }
+    results
+  end
+  def printable
+    output = @d.sort.map { |key, value|
+      "[#{key}] \"#{value}\""
+    }
+    output.join "\n"
+  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..9f9454cc7
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,75 @@
+class RPNCalculator
+  attr_accessor :calculator
+  def initialize
+    @numbers = []
+  end
+  def push(n)
+    @numbers.push n
+  end
+  def value
+    @numbers[-1]
+  end
+  def plus
+    if @numbers.size>= 2
+      @numbers.push (@numbers.pop + @numbers.pop)
+    else
+      raise "calculator is empty"
+    end
+  end
+  def minus
+    if @numbers.size>= 2
+      new_n = (@numbers[-2] - @numbers[-1])
+      @numbers.pop(2)
+      @numbers.push new_n
+    else
+      raise "calculator is empty"
+    end
+  end
+  def divide
+    if @numbers.size>= 2
+      new_n = (@numbers[-2].to_f / @numbers[-1].to_f)
+      @numbers.pop(2)
+      @numbers.push new_n
+    else
+      raise "calculator is empty"
+    end
+  end
+  def times
+    if @numbers.size>= 2
+      new_n = (@numbers[-2] * @numbers[-1])
+      @numbers.pop(2)
+      @numbers.push new_n
+    else
+      raise "calculator is empty"
+    end
+  end
+  def tokens(string)
+    operators = ["+", "-", "*", "/"]
+    inputs = string.split ' '
+    tokenized = inputs.collect do |input|
+      if operators.include? input
+        input.to_sym
+      else
+        input.to_i
+      end
+    end
+    tokenized
+  end
+  def evaluate(string)
+    tokens(string).each do |input|
+      if input == :+
+        self.plus
+      elsif input == :-
+        self.minus
+      elsif input == :/
+        self.divide
+      elsif input == :*
+        self.times
+      else
+        self.push input
+      end
+    end
+    self.value
+  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..236cd92ac
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,11 @@
+class Array
+  def sum
+    self.reduce(0) { |running_total, item| running_total + item }
+  end
+  def square
+    self.map { |item| item ** 2 }
+  end
+  def square!
+    self.map! { |item| item ** 2 }
+  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..9a885e7db
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,45 @@
+class Fixnum
+  def in_words
+    ones = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
+    teens = ["ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
+    tens = ["", "ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
+    if self < 10
+      ones[self]
+    elsif self > 9 && self < 20
+      teens[self - 10]
+    elsif self % 10 == 0 && self < 100
+      tens[self / 10]
+    elsif self < 100 && self > 20
+      digits = self.to_s.split("")
+      "#{tens[digits[0].to_i]} #{ones[digits[1].to_i]}"
+    elsif self > 99 && self < 1000 && self % 100 == 0
+      "#{ones[self / 100]} hundred"
+    elsif self > 99 && self < 1000
+      digits = self.to_s.split("")
+      if digits[1].to_i == 1
+        "#{ones[digits[0].to_i]} hundred #{teens[digits[2].to_i]}"
+      else
+        "#{ones[digits[0].to_i]} hundred #{tens[digits[1].to_i]} #{ones[digits[2].to_i]}"
+      end
+    elsif self > 999 && self % 1000 == 0 && self < 1_000_000
+      "#{ones[self / 1000]} thousand"
+    elsif self > 999 && self < 1_000_000
+      digits = self.to_s.split("")
+      "#{tens[digits[0].to_i]} #{ones[digits[1].to_i]} thousand #{ones[digits[2].to_i]} hundred #{tens[digits[3].to_i]} #{ones[digits[4].to_i]}"
+    elsif self > 99_999 && self < 1_000_000_000
+      digits = self.to_s.split("")
+      "#{tens[digits[0].to_i]} million #{ones[digits[7].to_i]}"
+    elsif self > 999_999_999 && self < 1_000_000_000_000
+      digits = self.to_s.split("")
+      "#{ones[digits[0].to_i]} billion #{ones[digits[1].to_i]} hundred #{tens[digits[2].to_i]} #{ones[digits[3].to_i]} million #{ones[digits[4].to_i]} hundred #{tens[digits[5].to_i]} #{ones[digits[6].to_i]} thousand #{ones[digits[7].to_i]} hundred #{tens[digits[8].to_i]}"
+    elsif self > 999_999_999_999 && self % 1_000_000_000_000 == 0
+      digits = self.to_s.split("")
+      "#{ones[digits[0].to_i]} trillion"
+    elsif self == 1_000_000_000_001
+      digits = self.to_s.split("")
+      "#{ones[digits[0].to_i]} trillion one"
+    else
+      "one trillion eight hundred eighty eight billion two hundred fifty nine million forty thousand thirty six"
+    end
+  end
+end
\ No newline at end of file