diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..503aede1e
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(name)
+  "Hello, #{name}!"
+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..324d5c39a
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,7 @@
+def ftoc(fahrenheit)
+  celcius = (fahrenheit - 32) * (5.0/9.0)
+end
+
+def ctof(celcius)
+  fahrenheit = celcius * (9.0/5.0) + 32
+end
diff --git a/02_calculator/calculator.rb b/02_calculator/calculator.rb
new file mode 100644
index 000000000..4224d2a87
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,46 @@
+def add(a, b)
+  total = a + b
+end
+
+def subtract(a, b)
+  total = a -b
+end
+
+def sum(array)
+  total = 0
+
+  array.each do |item|
+    total += item
+  end
+
+  total
+end
+
+def multiply(array)
+  total = 1
+
+  array.each do |item|
+    total *= item
+  end
+
+  total
+end
+
+def power(a, b)
+  total = 1
+
+  # total = a ** b
+  b.times do
+    total *= a
+  end
+
+  total
+end
+
+def factorial(a)
+  if a == 0 || a == 1
+    return 1
+  else
+    a * factorial(a - 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..559a71cc2 100644
--- a/02_calculator/calculator_spec.rb
+++ b/02_calculator/calculator_spec.rb
@@ -79,21 +79,41 @@
 
 describe "#multiply" do
 
-  it "multiplies two numbers"
+  it "multiplies two numbers" do
+    expect(multiply([2,2])).to eq(4)
+  end
+
+  it "multiplies several numbers" do
+    expect(multiply([2,2,3])).to eq(12)
+  end
 
-  it "multiplies several numbers"
-  
 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(2,3)).to eq(8)
+  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..2462dc829
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,29 @@
+def echo(input)
+  "#{input}"
+end
+
+def shout(input)
+  "#{input.upcase}"
+end
+
+def repeat(input, number=2)
+  (input + " ") * (number-1) + input
+end
+
+def start_of_word(string, position)
+  string[0..position-1]
+end
+
+def first_word(string)
+  all_words = string.split(" ")
+  all_words[0]
+end
+
+def titleize(string)
+  no_capitalization = ["and", "over", "the"]
+
+  all_words = string.split(" ")
+  all_words.each { |word| word.capitalize! unless no_capitalization.include?(word) }
+  all_words[0].capitalize!
+  all_words.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..947dea4de
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,45 @@
+def is_vowel?(character)
+  vowels = ["a", "e", "i", "o", "u"]
+
+  if vowels.include?(character)
+    true
+  else
+    false
+  end
+end
+
+
+def consonants(string)
+  result = ""
+  first = string[0]
+  second = string[1]
+  third = string[2]
+
+  if !is_vowel?(second) && !is_vowel?(third) || (second =="q" && third == "u")
+    word_begin = string[0..2]
+    result += string[3..-1] + word_begin + "ay"
+  elsif !is_vowel?(second) || (first =="q" && second == "u")
+    word_begin = string[0..1]
+    result += string[2..-1] + word_begin + "ay"
+  else
+    result += string[1..-1] + first + "ay"
+  end
+end
+
+
+def translate(string)
+  split_words = string.split(" ")
+  result = ""
+
+  if split_words.length > 1
+    translated = split_words.collect { |word| translate(word)}
+    return translated.join(" ")
+  end
+
+  if is_vowel?(string[0])
+    result += "#{string}ay"
+  else
+    consonants(string)
+  end
+
+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..0386d4af8
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,18 @@
+def reverser
+  result = []
+
+  yield.split.each do |word|
+    result << word.reverse
+  end
+
+  result.join(" ")
+end
+
+def adder(added_num=1)
+  result = yield
+  result += added_num
+end
+
+def repeater(num=1)
+  num.times { |item| 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..dd2a2081d
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,9 @@
+def measure(num=1)
+  first_time = Time.now
+
+  num.times { |item| yield }
+
+  second_time = Time.now
+
+  elapsed_time = (second_time - first_time)/num
+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..cec71b827
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,18 @@
+class Book
+  def title
+    @title
+  end
+
+  def title=(string)
+    @title = titlelize(string)
+  end
+
+  def titlelize(string)
+    no_capitalization = ["a", "an", "and", "in", "over", "of", "the"]
+
+    all_words = string.split(" ")
+    all_words.each { |word| word.capitalize! unless no_capitalization.include?(word) }
+    all_words[0].capitalize!
+    all_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..893e36d70
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,22 @@
+class Timer
+  attr_accessor :seconds
+
+  def initialize
+    @seconds = 0
+  end
+
+  def time_string
+    the_time = ""
+
+    secs = @seconds % 60
+    mins = (@seconds/60) % 60
+    hrs = @seconds/3600
+
+    the_time = "#{format(hrs)}:#{format(mins)}:#{format(secs)}"
+  end
+
+  def format(input)
+    input.to_s.length > 1 ? input.to_s : "0#{input.to_s}"
+  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..021b62675
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,37 @@
+class Temperature
+  def initialize(options={})
+    @fahrenheit = options[:f]
+    @celsius = options[:c]
+
+    @fahrenheit = in_fahrenheit if options[:c]
+    @celsius = in_celsius if options[:f]
+  end
+
+  def in_fahrenheit
+    @fahrenheit = @celsius * (9.0/5.0) + 32
+  end
+
+  def in_celsius
+    @celsius = (@fahrenheit - 32) * (5.0/9.0)
+  end
+
+  def self.from_celsius(celsius)
+    Temperature.new(c: celsius)
+  end
+
+  def self.from_fahrenheit(fahrenheit)
+    Temperature.new(f: fahrenheit)
+  end
+end
+
+class Celsius < Temperature
+  def initialize(celsius)
+    super(:c => celsius)
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize(fahrenheit)
+    super(:f => fahrenheit)
+  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..bc37e8d8a
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,47 @@
+class Dictionary
+  attr_accessor :entries
+
+  def initialize
+    @entries = {}
+  end
+
+  def add(listing)
+    if listing.is_a?(String)
+      @entries[listing] = nil
+    else
+      listing.each do |key, value|
+        @entries[key] = value
+      end
+    end
+  end
+
+  def keywords
+    @entries.keys.sort
+  end
+
+  def include?(listing)
+    @entries.include?(listing)
+  end
+
+  def find(input)
+    matches = {}
+    @entries.each do |key, value|
+      if key[0..input.length-1] == input
+        matches[key] = value
+      end
+    end
+
+    matches
+  end
+
+  def printable
+    print = []
+
+    @entries.sort.map do |key, value|
+      print << "[#{key}] \"#{value}\""
+    end
+
+    print.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..ade57d36a
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,76 @@
+class RPNCalculator
+  attr_accessor :calculator, :value
+
+  def initialize
+    @stack = []
+
+  end
+
+  def value
+    @stack.last
+  end
+
+  def push(a)
+    @stack << a
+  end
+
+  def plus
+    raise "calculator is empty" if @stack.length < 2
+
+    a = @stack.pop
+    b = @stack.pop
+    total = a + b
+
+    @stack << total
+  end
+
+  def minus
+    raise "calculator is empty" if @stack.length < 2
+
+    a = @stack.pop
+    b = @stack.pop
+    total = b - a
+
+    @stack << total
+  end
+
+  def times
+    raise "calculator is empty" if @stack.length < 2
+
+    a = @stack.pop.to_f
+    b = @stack.pop.to_f
+    total = b * a
+
+    @stack << total
+  end
+
+  def divide
+    raise "calculator is empty" if @stack.length < 2
+
+    a = @stack.pop.to_f
+    b = @stack.pop.to_f
+    total = b / a
+
+    @stack << total
+  end
+
+  def tokens(string)
+    string.split(" ").map do |token|
+      (token.match(/\d+/)) ? token.to_f : token.to_sym
+    end
+  end
+
+  def evaluate(string)
+    tokens(string).each do |token|
+      case token
+        when :+ then plus
+        when :- then minus
+        when :/ then divide
+        when :* then times
+        else push(token)
+      end # case
+    end # tokens.each
+
+    value
+  end # evaluate
+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..278400d5a
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,15 @@
+class Array
+
+  def sum
+    self.reduce(0, :+)
+  end
+
+  def square
+    self.collect { |num| num ** 2 }
+  end
+
+  def square!
+    self.collect! { |num| num ** 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..da47f21ac
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,52 @@
+class Fixnum
+
+  ONES = %w(one two three four five six seven eight nine)
+  TEENS = %w(eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen ten)
+  TENS = %w(ten twenty thirty forty fifty sixty seventy eighty ninety)
+  BIG_NUMS = [
+    [100, "hundred"],
+    [1000, "thousand"],
+    [1_000_000, "million"],
+    [1_000_000_000, "billion"],
+    [1_000_000_000_000, "trillion"],
+  ]
+
+  def in_words
+    num = self
+    output = ''
+
+    return "zero" if num == 0
+
+    BIG_NUMS.reverse.each do |limit, word|
+      if num > (limit - 1)
+        th_place = num / limit
+        if th_place > 0
+          output << "#{th_place.in_words} #{word}"
+          num -= (th_place * limit)
+          output << " " if num > 0
+        end
+      end
+    end
+
+    # conversions
+    tens_place = num / 10
+    ones_place = num - tens_place * 10
+
+    if tens_place == 1
+      output += TEENS[ones_place - 1]
+      return output
+    end
+
+    if tens_place > 1
+      output << TENS[tens_place - 1]
+      output << " " if ones_place > 0
+    end
+
+    if ones_place > 0
+      output << ONES[ones_place - 1]
+    end
+
+    output
+  end
+
+end