diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..d6fa1f7cb
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(someone)
+  "Hello, #{someone}!"
+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..79d693cf8
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,10 @@
+#farenheigh to celsius
+def ftoc(temperature)
+  celsius = (temperature.to_f - 32.0) * (5.0/9.0)
+end
+
+
+#celsius to fahrenheit
+def ctof(temperature)
+  fahrenheight = (temperature.to_f * (9.0/5.0)) + 32.0
+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..08b0c74b2
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,35 @@
+# add method
+def add(first, second)
+  first + second
+end
+
+#subtract method
+def subtract(first, second)
+  first - second
+end
+
+#sum method
+def sum(array)
+  sum = 0
+  array.each { |x| sum += x }
+  sum
+end
+
+#multiply method
+def multiply(*numbers)
+  product = 1
+  numbers.each { |x| product *= x}
+  product
+end
+
+#power method
+def power(a,b)
+  a ** b
+end
+
+#factorial method
+def factorial(n)
+  product = 1
+  (n).downto(1).each { |x| product *= x }
+  product
+end
diff --git a/02_calculator/calculator_spec.rb b/02_calculator/calculator_spec.rb
index fef7e9d00..88273468b 100644
--- a/02_calculator/calculator_spec.rb
+++ b/02_calculator/calculator_spec.rb
@@ -78,22 +78,40 @@
 # write tests and code for the following:
 
 describe "#multiply" do
+  it "multiplies two numbers" do
+    expect(multiply(5,7)).to eq(35)
+  end
 
-  it "multiplies two numbers"
-
-  it "multiplies several numbers"
-  
+  it "multiplies several numbers" do
+    expect(multiply(5,84,32,6)). to eq(80640)
+  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(4,3)). to eq(64)
+  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/04_pig_latin/pig_latin.rb b/04_pig_latin/pig_latin.rb
new file mode 100644
index 000000000..b876cb7d0
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,34 @@
+def translate(input)
+
+alphabet = ("a".."z").to_a
+vowels = ["a","e","i","o","u"]
+consonants = alphabet - vowels
+words = input.split(" ")
+
+
+
+  words.map do |word|
+
+    #word begins with vowel
+    if vowels.include?(word[0])
+      word << "ay"
+    #word begins with 2 consonants
+    elsif (consonants.include?(word[0]) && consonants.include?(word[1]) && consonants.include?(word[2])) || word[1..2].include?("qu")
+      add = word[0..2] + "ay"
+      word.delete!(word[0..2])
+      word << add 
+    elsif (consonants.include?(word[0]) && consonants.include?(word[1])) || word[0..1].include?("qu")
+      add = word[0..1] + "ay"
+      word.delete!(word[0..1])
+      word << add   
+    #word begins with 1 consonant
+    elsif consonants.include?(word[0])
+      add = word[0] + "ay"
+      word.delete!(word[0])
+      word << add
+    end
+  end
+
+words = words.join" ".to_s
+end
+
diff --git a/04_pig_latin/pig_latin_spec.rb b/04_pig_latin/pig_latin_spec.rb
index cc659edfd..8c5f05ad5 100644
--- a/04_pig_latin/pig_latin_spec.rb
+++ b/04_pig_latin/pig_latin_spec.rb
@@ -65,6 +65,16 @@
     expect(s).to eq("ethay ickquay ownbray oxfay")
   end
 
+  it "retains capitalized words" do
+    s = translate("The Quick Brown Fox")
+    expect(s).to eq("eThay ickQuay ownBray oxFay")
+  end
+
+  it "retains punctuation" do
+    s = translate("something 'here' should still translate...!")
+    expect(s).to eq("omethingsay 'erehay' ouldshay illstay anslatetray...!")
+  end
+
   # Test-driving bonus:
   # * write a test asserting that capitalized words are still capitalized (but with a different initial capital letter, of course)
   # * retain the punctuation from the original phrase
diff --git a/05_silly_blocks/silly_blocks.rb b/05_silly_blocks/silly_blocks.rb
new file mode 100644
index 000000000..c7aaf198d
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,13 @@
+def reverser
+  words = yield.split" "
+  words.map {|word| word.reverse }.join(" ")
+end
+
+def adder(n=1)
+  yield(n) + 1 + (n-1)
+end
+
+def repeater(number=1)
+  number.times {|x| yield }
+end
+
diff --git a/06_performance_monitor/performance_monitor.rb b/06_performance_monitor/performance_monitor.rb
new file mode 100644
index 000000000..f6a2ccbec
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,5 @@
+def measure(n=1)
+  start_time = Time.now
+  n.times {|n| yield }
+  (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..9796bdc5e
--- /dev/null
+++ b/07_hello_friend/friend.rb
@@ -0,0 +1,11 @@
+class Friend
+
+def greeting(someone=nil)
+  if someone == nil
+    "Hello!"
+  else
+    "Hello, #{someone}!"
+  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..df8d68c52
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,18 @@
+class Book
+
+attr_accessor :title
+
+def title
+  @title = @title.split(" ")
+  articles = ["the","a","and","in","of","an"]
+  @title.map do |word|
+    word[0] = word[0].capitalize unless articles.include?(word)
+  end
+  @title[0] = @title[0].capitalize
+  @title.join(" ")
+end
+
+
+end
+
+
diff --git a/09_timer/timer.rb b/09_timer/timer.rb
new file mode 100644
index 000000000..8a3df7a58
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,15 @@
+class Timer
+
+attr_accessor :seconds
+
+def seconds
+  0
+end
+
+def time_string
+  default = Time.at(0)+18000
+  @seconds
+  (default + @seconds).strftime("%H:%M:%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..1a5561b32
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,50 @@
+class Temperature 
+
+def initialize(values)
+  @f = values[:f]
+  @c = values[:c]
+  @c.nil? ? @c = Temperature.ftoc(@f) : @f = Temperature.ctof(@c)
+end
+
+
+def in_fahrenheit
+  @f 
+end
+
+def in_celsius
+  @c
+end
+
+#factory methods
+def self.from_celsius(values)
+  Temperature.new(:c => values)
+end
+
+def self.from_fahrenheit(values)
+  Temperature.new(:f => values)
+end
+
+#test-driving bonus:
+def self.ftoc(values)
+  (values - 32) * (5.0/9.0)
+end
+
+def self.ctof(values)
+  (values * (9.0/5.0)) + 32.0
+end
+end
+
+
+#subclasses
+
+class Celsius < Temperature
+  def initialize(values)
+    super(:c => values)
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize(values)
+    super(:f => values)
+  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..60c3ebc40
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,48 @@
+class Dictionary
+
+def initialize
+  @entries = {}
+end
+
+def entries
+  @entries
+end
+
+def add(entry, value=nil)
+  if entry.is_a?Hash
+    entry.each do |word, definition|
+      @entries[word] = definition
+    end
+  elsif entry.is_a?String
+    @entries[entry] = nil
+  end
+end
+
+def keywords
+  @entries.keys.sort
+end
+
+def include?(word)
+  keywords.include?(word)
+end
+
+def find(word)
+  result = {}
+  @entries.each do |key, value|
+    if key.start_with?(word)
+      result[key] = value
+    end
+  end
+  result
+end
+
+def printable
+  print = @entries.sort.map do |key, value|
+    "[#{key}] \"#{value}\""
+  end
+  print.join"\n"
+end
+
+
+#class ends here
+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..782e10b16
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,55 @@
+class RPNCalculator
+
+def initialize
+  @numbers = []
+end
+
+def push(value)
+  @numbers << value.to_f
+end
+
+def calc(operation)
+  raise "calculator is empty" if @numbers.size < 2
+  calculation = @numbers[-2].send(operation, @numbers[-1])
+  @numbers.pop(2)
+  @numbers << calculation
+end
+
+def plus
+  calc(:+)
+end
+
+def minus
+  calc(:-)
+end  
+
+def divide
+  calc(:/)
+end
+
+def times
+  calc(:*)
+end
+
+def tokens(string)
+  string.split(" ").map do |item|
+    item =~ /[\+\-\*\/]/ ? item.to_sym : item.to_f
+  end
+end
+
+def evaluate(string)
+  tokens(string).each do |item|
+    item.is_a?(Float) ? @numbers<<item : calc(item)
+  end
+  value
+end
+
+def value
+  @numbers.last
+end
+end
+
+
+# rewrite with everything with num1.send(operation, num2) method
+# @numbers.pop(2).inject(operator)
+#[1, 2, 3, 4, 5] -- [4,6].inject(:*)
\ 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..107e9bfa8
--- /dev/null
+++ b/13_xml_document/xml_document.rb
@@ -0,0 +1,32 @@
+class XmlDocument
+
+def initialize(indent=false)
+  @indent = indent
+  @indent_level = 0
+end
+
+def method_missing(method_name, *input, &block)
+  input = input[0] || {}
+  xml = ""
+  xml << ("  " * @indent_level) if @indent
+  xml << "<#{method_name}"
+  input.each do |key, value|
+    xml << " #{key}='#{value}'"
+  end
+  if block_given?
+    xml << ">"
+    xml << "\n" if @indent
+    @indent_level += 1
+    xml << yield
+    @indent_level -= 1
+    xml << ("  " * @indent_level) if @indent
+    xml << "</#{method_name}>"
+    xml << "\n" if @indent
+  else
+    xml << "/>"
+    xml << "\n" if @indent
+  end
+  xml
+  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..250239301
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,18 @@
+class Array
+
+def sum
+  self.reduce(0, :+)
+end
+
+def square
+  return [] if self.empty?
+  self.map {|x| x * x}
+end
+
+def square!
+  return [] if self.empty?
+  self.map! {|x| x * x}
+end
+
+
+end
\ No newline at end of file