diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..5a5ad056e
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(who)
+  "Hello, #{who}!"
+end
diff --git a/01_temperature/temperature.rb b/01_temperature/temperature.rb
new file mode 100644
index 000000000..9943bab77
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,7 @@
+def ftoc(f)
+  (f-32.0) * (5.0/9)
+end
+
+def ctof(c)
+  (c * (9.0/5)) + 32
+end
diff --git a/02_calculator/calculator.rb b/02_calculator/calculator.rb
new file mode 100644
index 000000000..8e0f4d58c
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,26 @@
+def add (num1, num2)
+  num1 + num2
+end
+
+def subtract (num1, num2)
+  num1 - num2
+end
+
+def sum (numbers)
+  #numbers.reduce(0) { |current_num, next_num| current_num + next_num }
+  numbers.reduce(0, :+) 
+end
+
+def multiply (*args)
+  args.reduce(1, :*)
+end
+
+def power (base, exponent)
+  base ** exponent
+end
+
+def factorial number
+	accumulator = 1
+	number.downto(1) { |i| accumulator *= i }
+	accumulator
+end
\ No newline at end of file
diff --git a/02_calculator/calculator_spec.rb b/02_calculator/calculator_spec.rb
index fef7e9d00..4bb529c19 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 several numbers"
-  
+  it "multiplies two numbers" do
+    expect(multiply(3,4)).to eq(12)
+  end
+  it "multiplies several numbers" do
+    expect(multiply(3,4,2)).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(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/03_simon_says/simon_says.rb b/03_simon_says/simon_says.rb
new file mode 100644
index 000000000..f9f82fc0c
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,29 @@
+def echo(word)
+  return word
+end
+
+def shout(word)
+  return word.upcase
+end
+
+def repeat(word, iterations=2)
+  repeats = []
+  iterations.times { repeats << word }
+  return repeats.join(" ")
+end
+
+def start_of_word(word, amount)
+  return word.slice(0, amount)
+end
+  
+def first_word(words)
+  return words.split(" ")[0]
+end
+
+def titleize(string)
+  array = string.split(" ")
+  
+  return array.map.with_index do |word, index|
+  	 (index == 0) || (word == array[-1]) || (word.length > 4) ? word.capitalize : word
+  end.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..f07bee78a
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,43 @@
+VOWELS = ['a', 'e', 'i', 'o', 'u']
+
+def translate(string)
+  words = string.split(" ")
+
+  return words.map do |word|
+      translate_word word
+  end.join(" ")
+  
+end
+
+
+def translate_word(word)
+  
+  working_index = nil
+  group1, group2, groups = '', '', ''
+  
+  if word[0..1] == 'qu' || word[1..2] == 'qu'
+    regex = word.scan(/\As?q[a-z]/)
+    working_index = regex[0].length
+    group1 = word[0...working_index]
+    group2 = word[working_index..-1]
+
+  elsif !(VOWELS.include? word[0])
+    regex = word.scan(/\A[^aeiou]+/)
+    working_index = regex[0].length
+    group1 = word[0...working_index]
+    group2 = word[working_index..-1]
+    
+  else
+    group2 = word
+  end
+    
+  groups = group2 + group1
+  if groups.end_with? 'a'
+    return groups + 'y'
+  else
+    return groups + 'ay'
+  end
+  
+end
+
+
diff --git a/05_silly_blocks/silly_blocks.rb b/05_silly_blocks/silly_blocks.rb
new file mode 100644
index 000000000..fb5648266
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,11 @@
+def reverser 
+  return yield.split(" ").map { |word| word.reverse }.join(" ") 
+end
+
+def adder(int = 1)
+  return yield + int
+end
+
+def repeater(i=3)
+	return i.times { yield }
+end
diff --git a/06_performance_monitor/performance_monitor.rb b/06_performance_monitor/performance_monitor.rb
new file mode 100644
index 000000000..c3190014c
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,20 @@
+def measure(i=1)
+  i = i.size if i.is_a?(Array)
+  
+  total = 0
+  
+  i.times do 
+    if block_given?
+      start_time = Time.now
+      yield
+      total += Time.now - start_time
+    else
+      start_time = Time.now
+      total += Time.now - start_time
+    end
+  end
+    
+  return total / i
+  
+end
+
diff --git a/07_hello_friend/friend.rb b/07_hello_friend/friend.rb
new file mode 100644
index 000000000..68f5ab292
--- /dev/null
+++ b/07_hello_friend/friend.rb
@@ -0,0 +1,6 @@
+class Friend
+  def greeting(name = nil)
+    name ? "Hello, #{name}!" : "Hello!" 
+  end
+end
+
diff --git a/08_book_titles/book.rb b/08_book_titles/book.rb
new file mode 100644
index 000000000..153b2567f
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,26 @@
+class Book
+  #be better to seperate by exceptions, conjuctions, and prepositions?
+  #most effecient way to do an_array.include?)
+  
+  #exceptions
+  CONJUNCTIONS = %w[and]
+  PREPOSITIONS = %w[in of]
+  OTHER_WORDS = %w[the a an]
+  
+  ALL_EXCEPTIONS = CONJUNCTIONS + PREPOSITIONS + OTHER_WORDS
+  
+  EXCEPTIONS = %w[the a an]	
+  
+	def title=(name)
+		@name = name  
+	end
+	  	
+	def title  	
+	 #@name.split.map(&:capitalize).join(" ")
+	
+    @name.split.map.with_index do |word, index|
+      !ALL_EXCEPTIONS.include?(word) || index == 0 ? word.capitalize : word
+      end.join(" ") #just keeping it playful with some spaghetti code :-)
+	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..de559d292
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,50 @@
+class Timer
+
+  attr_accessor :seconds
+  
+  def initialize(secs = 0)
+    @seconds = secs
+    @minutes = 0
+    @hours   = 0
+  end
+  
+  # def seconds
+  #   @seconds
+  # end
+  
+  # def seconds=(seconds)
+  #   @seconds = seconds
+  # end
+  
+  def seconds_to_minutes_hours
+    while @seconds >= 60
+      if (@seconds - 3600 > 0)
+        @hours += 1
+        @seconds -= 3600
+        
+      elsif (@seconds - 60 > 0)
+        @minutes += 1
+        @seconds -= 60
+      end
+    end
+    
+  end
+  
+  def time_string
+    
+    seconds_to_minutes_hours
+    
+    #INT TO STRING CONVERSIONS
+    @sec_str = @seconds.to_s
+    @min_str = @minutes.to_s
+    @hour_str = @hours.to_s
+    
+    @sec_str = '0' + @sec_str if @seconds < 10
+    @min_str = '0' + @min_str if @minutes < 10
+    @hour_str = '0' + @hour_str if @hours < 10
+    
+    
+    "#{@hour_str}:#{@min_str}:#{@sec_str}"
+    
+  end
+end 
diff --git a/10_temperature_object/temperature.rb b/10_temperature_object/temperature.rb
new file mode 100644
index 000000000..6422565d0
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,36 @@
+class Temperature
+
+  def initialize hash
+    @fahrenheit = hash[:f]
+    @celsius = hash[:c]
+  end
+  
+  def in_fahrenheit
+  	@fahrenheit ||= @celsius * (9.0/5) + 32
+  end 
+  
+  def in_celsius
+    @celsius ||= (@fahrenheit - 32.0) * (5.0 / 9)  
+  end
+  
+  def self.from_celsius(degrees)
+    self.new(:c => degrees)
+  end
+  
+  def self.from_fahrenheit(degrees)
+    self.new(:f => degrees)
+  end  
+
+end
+
+class Celsius < Temperature
+  def initialize degrees
+    @celsius = degrees
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize degrees
+    @fahrenheit = degrees
+  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..1cc5ecf95
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,43 @@
+class Dictionary
+	
+	attr_reader :entries, :keywords
+	def initialize
+		@entries = Hash.new()
+		@keywords = []
+	end
+	
+	def add(entry)
+	  if String === entry
+	  	@keywords << entry
+	  	@entries.store(entry, nil)
+	  else
+		  @entries.merge!(entry)
+		  @keywords << entry.keys[0]
+	  end
+	  @keywords.sort!
+	end
+	
+	def include?(keyword)
+	  @keywords.include?(keyword)
+	end
+	
+	def find(word)
+		# include?(word) ? match_it(word) : {}
+		matches = {}
+	  @keywords.each do |keyword|
+	    if keyword.start_with?(word)
+	      matches[keyword] = @entries[keyword]
+	    end
+	 end
+	 return matches
+	end
+
+  def printable
+    output = []
+    keywords.each do |keyword|
+      output << "[#{keyword}] \"#{entries[keyword]}\""
+    end
+    output * "\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..f37e7f729
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,83 @@
+#be able to sequence go back to back with operations w/o creating new obj
+class RPNCalculator
+  
+  attr_reader :value
+  
+  # def value
+  #   @value
+  # end
+  
+  def initialize
+    @stack = []
+    @value = 0
+  end
+  
+  def push number
+    @stack << number
+  end
+  
+  def plus
+    raise "calculator is empty" if @stack.length < 2
+    addition = @stack.pop + @stack.pop
+  
+    @stack.push(addition)
+    @value = addition
+  end
+  
+  def minus
+    raise "calculator is empty" if @stack.length < 2
+    subtraction = (@stack.pop - @stack.pop) * -1
+    
+    @stack.push(subtraction)
+    @value = subtraction
+  end  
+  
+  def divide
+    raise "calculator is empty" if @stack.length < 2
+    last = @stack.pop.to_f
+    second_last = @stack.pop.to_f
+    action = second_last / last
+    
+    @stack.push(action)
+    @value = action
+  end   
+  
+  def times
+    raise "calculator is empty" if @stack.length < 2
+    last = @stack.pop.to_f
+    second_last = @stack.pop.to_f
+    action = second_last * last
+    
+    @stack.push(action)
+    @value = action
+  end     
+  
+  def tokens string
+    string.split(" ").map do |token|
+      (token.match(/\d+/)) ? token.to_i : token.to_sym
+    end
+    
+  end
+  
+  def evaluate string
+    
+    string.split(" ").each do |item|
+      if item.match(/\d+/)
+        @stack.push(item.to_f)
+      elsif item == '+'
+        plus
+      elsif item == '-'
+        minus
+      elsif item == '*'
+        times
+      elsif item == '/'
+        divide
+      end
+    end
+    value
+    
+  end
+
+  
+
+end
diff --git a/14_array_extensions/array_extensions.rb b/14_array_extensions/array_extensions.rb
new file mode 100644
index 000000000..6175885f5
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,14 @@
+class Array
+	def sum
+		self.inject(0, &:+)
+	end
+	
+	def square 
+	  self.map { |n| n ** 2 }
+	end
+	
+	def square! 
+	  self.map! { |n| n ** 2 }
+	end	
+	
+end
diff --git a/15_in_words/in_words.rb b/15_in_words/in_words.rb
new file mode 100644
index 000000000..4f4d9703c
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,79 @@
+class Fixnum
+  
+  SUB_TEN = {1=>"one", 2=>"two", 3=>"three", 4=>"four", 5=>"five", 6=>"six", 7=>"seven", 8=>"eight", 9=>"nine"}
+  SUB_TWENTY = {11=>"eleven", 12=>"twelve", 13=>"thirteen", 14=>"fourteen", 15=>"fifteen", 16=>"sixteen", 17=>"seventeen", 18=>"eighteen", 19=>"nineteen"}
+  TENS = {10=>"ten", 20=>"twenty", 30=>"thirty", 40=>"forty", 50=>"fifty", 60=>"sixty", 70=>"seventy", 80=>"eighty", 90=>"ninety"}
+  
+  DIGITS = SUB_TEN.merge(SUB_TWENTY).merge(TENS)
+  
+  VALUES = ['thousand', 'million', 'billion', 'trillion']
+  
+  def in_words
+    if self.zero?
+      return "zero"
+    elsif DIGITS[self]
+      return DIGITS[self]
+    else
+      return convert(self)
+    end
+  end
+  
+  
+  def convert(number)
+    first = three_digit_splitter(number)
+    wanted_values = values_selection(first.length)
+
+    output = first.map do |i|
+    	current = wanted_values.shift
+    	three_places(i,current) 
+    end
+    	
+    output.reject { |i| i.empty? }.join(" ")
+  end
+  
+    
+  def three_places(n, current)
+    output = []
+  	
+    a, b = n.divmod(100)
+    
+    unless a.zero?
+	    output << DIGITS[a]
+	    output << 'hundred'
+    end
+      
+    if DIGITS[b]
+      output << DIGITS[b]
+    else
+      tens, ones = b.divmod(10)
+      tens *= 10  
+    
+      output << DIGITS[tens]
+      output << DIGITS[ones]
+    end
+   
+    output << current unless b.zero?
+  
+    output.compact!
+    output.join(" ")
+  end
+    
+    
+  def three_digit_splitter(number)  
+    reversed_string = number.to_s.reverse
+    
+    split_array = reversed_string.scan(/\d{3}|\d{2}|\d{1}/).reverse
+    split_array.map! { |x| x.reverse.to_i }
+  end
+  
+    
+  def values_selection(size)
+  	if size >= 2
+  		VALUES[0..(size-2)].reverse
+  	else
+  		[]
+  	end
+  end   
+  
+  
+end
diff --git a/15_in_words/in_words_spec.rb b/15_in_words/in_words_spec.rb
index 1f5768575..fdaee9293 100644
--- a/15_in_words/in_words_spec.rb
+++ b/15_in_words/in_words_spec.rb
@@ -89,7 +89,8 @@
     expect(10_000_001.in_words).to eq('ten million one')
   end
 
-  it "reads billions" do
+  it "read
+  's billions" do
     expect(1_234_567_890.in_words).to eq('one billion two hundred thirty four million five hundred sixty seven thousand eight hundred ninety')
   end