diff --git a/00_hello/hello.rb b/00_hello/hello.rb
new file mode 100644
index 000000000..6a559c055
--- /dev/null
+++ b/00_hello/hello.rb
@@ -0,0 +1,8 @@
+#write your code here
+def hello
+	"Hello!"
+end
+
+def greet which_person
+	"Hello, " + which_person + "!"
+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..78d1cd471
--- /dev/null
+++ b/01_temperature/temperature.rb
@@ -0,0 +1,8 @@
+#write your code here
+def ftoc farenheit
+	centigrade = (farenheit - 32.0) * 5.0 / 9.0
+end
+
+def ctof centigrade
+	farenheit = centigrade * 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..2ee6a2929
--- /dev/null
+++ b/02_calculator/calculator.rb
@@ -0,0 +1,49 @@
+#write your code here
+def add first_num, second_num
+	result = first_num + second_num
+end
+
+def subtract first_num, second_num
+	result = first_num - second_num
+end
+
+def sum array
+	result = 0;
+	array.length.times do |i|
+		result = result + array[i]
+	end
+	result
+end
+
+def multiply first_num, second_num
+	result = first_num * second_num
+end
+
+def multiply_arr array
+	result = 1;
+	array.length.times do |i|
+		result = result * array[i]
+	end
+	result
+end
+
+def power first_num, second_num
+	result = first_num
+	(second_num - 1).times do
+		result = result * first_num
+	end
+	result
+end
+
+def fact number
+	result = 1
+	number.times do |i|
+		result = result * (i + 1)
+	end
+	if(number == 0)
+		0
+	else
+		result
+	end
+end
+
diff --git a/03_simon_says/simon_says.rb b/03_simon_says/simon_says.rb
new file mode 100644
index 000000000..f00c66330
--- /dev/null
+++ b/03_simon_says/simon_says.rb
@@ -0,0 +1,46 @@
+#write your code here
+def echo what_to_echo
+	what_to_echo
+end
+
+def shout what_to_shout
+	what_to_shout.upcase
+end
+
+def repeat what_to_repeat, how_many_times = 2
+	result = ""
+	(how_many_times - 1).times do
+		result = result + what_to_repeat + " "
+	end
+	result = result + what_to_repeat
+end
+
+def start_of_word the_word, how_many_letters
+	how_many_letters_m_1 = how_many_letters - 1
+	result = the_word[0..how_many_letters_m_1]
+end
+
+def first_word the_sentence
+	the_first_word = the_sentence.split
+	the_first_word[0]
+end
+
+def titleize the_sentence
+	little_words = ["and", "or", "over", "but", "the"] 
+	the_split_version = the_sentence.split
+	(the_split_version.length - 1).times do |i|
+		if(i != 0)
+			if(little_words.include? the_split_version[i])
+				the_split_version[i] = the_split_version[i] + " "
+			else
+				the_split_version[i].capitalize!
+				the_split_version[i] = the_split_version[i] + " "
+			end
+		else
+				the_split_version[i].capitalize!
+				the_split_version[i] = the_split_version[i] + " "
+		end
+	end
+	the_split_version[the_split_version.length - 1].capitalize!
+	the_split_version.join
+end
diff --git a/04_pig_latin/pig_latin.rb b/04_pig_latin/pig_latin.rb
new file mode 100644
index 000000000..9f3605685
--- /dev/null
+++ b/04_pig_latin/pig_latin.rb
@@ -0,0 +1,45 @@
+def translate the_sentence
+	vowels_array = ["a", "e", "i", "o" , "u"]
+	the_words = the_sentence.split
+	the_words.length.times do |i|
+		the_word = the_words[i]
+		if (vowels_array.include? the_word[0])
+			the_word = the_word + "ay"
+		else
+			the_word = word_piggy(the_word)
+			if (vowels_array.include? the_word[0])
+				the_word = word_piggy(the_word) + "ay"
+			else
+				the_word = word_piggy(the_word)
+				if (vowels_array.include? the_word[0])
+					the_word = word_piggy(the_word) + "ay"
+				else
+					the_word = word_piggy(the_word)
+					if (vowels_array.include? the_word[0])
+						the_word = word_piggy(the_word) + "ay"
+					else
+						the_word = word_piggy(the_word)
+					end
+				end
+			end
+		end
+		the_word = the_word + " "
+ 		the_words[i] = the_word
+	end
+	new_words = the_words.join
+ 	new_words.chomp(" ")
+end
+
+def word_piggy the_word
+	vowels_array = ["a", "e", "i", "o" , "u"]
+	if (the_word[0..1] == "qu")
+		x = the_word.length - 1
+		new_word = the_word[2..x] + "qu" 
+	elsif (vowels_array.include? the_word[0])
+		new_word = the_word
+	else
+		x = the_word.length - 1
+		new_word = the_word[1..x] + the_word[0]
+	end
+	new_word
+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..e9e779a33
--- /dev/null
+++ b/05_silly_blocks/silly_blocks.rb
@@ -0,0 +1,22 @@
+def reverser
+	str = yield
+	str_arr = str.split(" ")
+	str_arr.each do |string|
+		string.reverse!
+	end
+	new_arr = []
+	str_arr.size.times do |index|
+		new_arr << str_arr[index]
+		new_arr << " "
+	end
+	new_arr.join.strip
+end
+
+def adder (num = 1)
+	value = yield
+	value += num
+end
+
+def repeater (num = 1)
+	num.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..328b2b4f3
--- /dev/null
+++ b/06_performance_monitor/performance_monitor.rb
@@ -0,0 +1,11 @@
+def measure(num = 1)
+	cur_time = Time.now
+	all_times = []
+	num.times {
+		cur_time = Time.now
+		yield
+		after_time = Time.now
+		all_times << after_time - cur_time
+	}
+	all_times.inject(0) { |sum, el| sum + el } / all_times.size
+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..529400ce4
--- /dev/null
+++ b/07_hello_friend/friend.rb
@@ -0,0 +1,5 @@
+class Friend
+	def greeting (string = "")
+		(string.size > 0) ? "Hello, #{string}!"  : "Hello!" 
+	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..68cae77ae
--- /dev/null
+++ b/08_book_titles/book.rb
@@ -0,0 +1,21 @@
+class Book
+# write your code here
+	attr_accessor :title
+	def initialize
+		
+	end
+	def title=(title)
+		exceptions = ["a", "the", "and", "an", "in", "and", "of"]
+		title_words = title.split
+		title_words.length.times do |i|
+			if((i != 0) && (exceptions.include? title_words[i]))
+				title_words[i] = title_words[i] + " "
+			else
+				title_words[i].capitalize!
+				title_words[i] = title_words[i] + " "
+			end
+ 		end
+ 		@title = title_words.join
+ 		@title = @title.chomp(" ")
+	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..c0f888c9b
--- /dev/null
+++ b/09_timer/timer.rb
@@ -0,0 +1,32 @@
+class Timer
+  #write your code here
+  attr_accessor :hours, :minutes, :seconds, :time_string
+
+  def initialize 
+  	@seconds = 0
+  	@hours = 0
+  	@minutes = 0
+  	@time_string = "00:00:00"
+  end
+  def seconds=(seconds)
+  	@seconds = seconds
+  	if(seconds > 3599)
+  		@hours = seconds / 3600
+  		@minutes = (seconds - (@hours * 3600)) / 60
+  		@seconds = seconds - (@hours * 3600) - (@minutes * 60)
+  	elsif(seconds > 59)
+  		@seconds = seconds % 60
+  		@minutes = seconds / 60
+  		@hours = 0
+  	else
+  		@seconds = seconds
+  		@hours = 0
+  		@minutes = 0
+  	end
+  	second_string = "%0.2d" % [@seconds]
+  	minute_string = "%0.2d" % [@minutes]
+  	hour_string = "%0.2d" % [@hours]
+  	@time_string = hour_string + ":" + minute_string + ":" + second_string
+  end
+
+end
diff --git a/10_temperature_object/temperature.rb b/10_temperature_object/temperature.rb
new file mode 100644
index 000000000..9b74bd9f3
--- /dev/null
+++ b/10_temperature_object/temperature.rb
@@ -0,0 +1,41 @@
+class Temperature
+	@in_fahrenheit
+	@in_celsius
+	def initialize(options={})
+		if options[:f]
+			@in_fahrenheit = options[:f]
+			in_celsius
+		end
+		if options[:c]
+			@in_celsius = options[:c]
+			in_fahrenheit
+		end
+	end
+
+	def self.from_celsius(cel_deg)
+    	new(:c => cel_deg)
+  	end
+  	def self.from_fahrenheit(far_deg)
+    	new(:f => far_deg)
+  	end
+
+	def in_fahrenheit
+		@in_fahrenheit = (@in_celsius) * 9.0 / 5.0 + 32.0
+	end
+
+	def in_celsius
+		@in_celsius = (@in_fahrenheit - 32.0) * 5.0 / 9.0
+	end
+end
+
+class Celsius < Temperature
+	def initialize(deg)
+		super(:c => deg)
+	end
+end
+
+class Fahrenheit < Temperature
+	def initialize(deg)
+		super(:f => deg)
+	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..9e479342a
--- /dev/null
+++ b/11_dictionary/dictionary.rb
@@ -0,0 +1,45 @@
+class Dictionary
+	@entries
+	@printable_output
+	def initialize
+		@entries = {}	
+	end
+	def entries
+		@entries
+	end
+	def add(hash={})
+		if hash.is_a? Hash
+			hash.each do |key, value|
+				@entries[key] = value
+			end
+		else
+			@entries[hash] = nil
+		end
+		@entries
+	end
+	def keywords
+		@entries.keys.sort
+	end
+
+	def include?(string)
+		@entries.include? string
+	end
+
+	def find(string)
+		result = Hash.new
+		if @entries.empty? || string == 'nothing'
+			{}
+		else
+			@entries.select{|key, value| key.include? string } 
+		end
+	end
+
+	def printable
+		@printable_output = ""
+		@sorted_entries = @entries.sort_by {|key, value| key}
+		@sorted_entries.each do |key, value|
+			@printable_output = @printable_output + "\[#{key}\]" + " \"#{value}\"" + "\n"
+		end
+		@printable_output.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..93b0e2701
--- /dev/null
+++ b/12_rpn_calculator/rpn_calculator.rb
@@ -0,0 +1,107 @@
+class RPNCalculator
+	@calculator
+	@value
+	@value1
+	@value2
+	def plus
+		if @calculator.size > 1
+			@value1 = @calculator.pop
+			@value2 = @calculator.pop
+			@value = @value2 + @value1
+			@calculator << @value
+		else
+			begin
+     			raise "calculator is empty"
+ 			end
+		end
+	end
+
+	def minus
+		if @calculator.size > 1
+			@value1 = @calculator.pop
+			@value2 = @calculator.pop
+			@value = @value2 - @value1
+			@calculator << @value
+		else
+			begin
+     			raise "calculator is empty"
+ 			end
+		end
+	end
+
+	def divide
+		if @calculator.size > 1
+			@value1 = @calculator.pop
+			@value2 = @calculator.pop
+			@value = @value2.to_f / @value1.to_f
+			@calculator << @value
+		else
+			begin
+     			raise "calculator is empty"
+ 			end
+		end
+	end
+
+	def times
+		if @calculator.size > 1
+			@value1 = @calculator.pop
+			@value2 = @calculator.pop
+			@value = @value2.to_f * @value1.to_f
+			@calculator << @value
+		else
+			begin
+     			raise "calculator is empty"
+ 			end
+		end
+	end
+
+	def initialize
+		@calculator = []
+	end
+
+	def push(num)
+		@calculator << num
+	end
+
+	def value
+		@value
+	end
+
+	def tokens(string)
+		tokens_string = string.split(" ")
+		tokens_array = []
+		tokens_string.each do |item|
+			case item
+			when "+" 
+				tokens_array << item.to_sym
+			when "-" 
+				tokens_array << item.to_sym
+			when "*" 
+				tokens_array << item.to_sym
+			when "/" 
+				tokens_array << item.to_sym
+			else 
+				tokens_array << item.to_i
+			end	
+		end
+		tokens_array
+	end
+
+	def evaluate(string)
+		tokens_array = tokens(string)
+		tokens_array.each do |item|
+			if item.is_a? Integer
+				push(item)
+			elsif item.to_s == "+"
+				plus
+			elsif item.to_s == "-"
+				minus
+			elsif item.to_s == "*"
+				times
+			elsif item.to_s == "/"
+				divide			
+			end
+		end
+		@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..8da7af934
--- /dev/null
+++ b/14_array_extensions/array_extensions.rb
@@ -0,0 +1,23 @@
+class Array
+	def sum
+		if self.size < 1
+			0
+		else
+			self.inject(0) {|sum, item| sum += item}
+		end
+	end
+	def square
+		if self.size < 1
+			[]
+		else
+			self.map {|item| item ** 2}
+		end
+	end
+	def square!
+		if self.size < 1
+			[]
+		else
+			self.map! {|item| item ** 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..c9e98cc55
--- /dev/null
+++ b/15_in_words/in_words.rb
@@ -0,0 +1,162 @@
+class Fixnum
+
+	
+    def spit_out_string (index, which)
+		onesPlace = ['one',     'two',       'three',    'four',     'five',
+		        'six',     'seven',     'eight',    'nine']
+		tensPlace = ['ten',     'twenty',    'thirty',   'forty',    'fifty',
+		        'sixty',   'seventy',   'eighty',   'ninety']
+		teenagers = ['eleven',  'twelve',    'thirteen', 'fourteen', 'fifteen',
+		        'sixteen', 'seventeen', 'eighteen', 'nineteen']
+		if which == 1
+			onesPlace[index]
+		elsif which == 2
+			tensPlace[index]
+		else
+			teenagers[index]
+		end
+    end
+
+	def in_words
+		if self < 0  # No negative numbers.
+			return 'Please enter a number that isn\'t negative.'
+		end
+		if self == 0
+			return 'zero'
+		end
+		numString = ''  # This is the string we will return.
+
+		left  = self
+
+		write = left/1000000000000          # How many hundreds left to write out?
+		left  = left - write*1000000000000  # Subtract off those hundreds.
+
+		if write > 0
+			trillions  = less_than_trillions write
+			numString = numString + trillions + ' trillion'
+		
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+		numString = numString + less_than_trillions(left)
+
+		numString
+	end
+
+	def less_than_10 (number)
+		left = number
+		numString = ""
+		write = left/10          # How many tens left to write out?
+		left  = left - write*10  # Subtract off those tens.
+
+		if write > 0
+			if ((write == 1) and (left > 0))
+				index = left-1
+				numString = numString + spit_out_string(index, 3)
+				left = 0
+			else
+				index = write-1	
+				numString = numString + spit_out_string(index, 2)
+			end
+
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+
+		write = left  # How many ones left to write out?
+		left  = 0     # Subtract off those ones.
+
+		if write > 0
+			index = write-1
+			numString = numString + spit_out_string(index, 1)
+		end
+
+		numString
+	end
+
+	def less_than_hundred (number)
+		numString = ""
+		numString = numString + less_than_10(number)
+		numString
+	end
+
+	def less_than_thousand (number)
+		numString = ""
+		left = number
+		write = left/100          # How many hundreds left to write out?
+		left  = left - write*100  # Subtract off those hundreds.
+
+		if write > 0
+			hundreds  = less_than_hundred write
+			numString = numString + hundreds + ' hundred'
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+		numString = numString + less_than_10(left)
+
+		numString
+	end
+
+	def less_than_millions (number)
+		numString = ""
+		left = number
+		write = left/1000          # How many hundreds left to write out?
+		left  = left - write*1000  # Subtract off those hundreds.
+
+		if write > 0
+			thousands  = less_than_thousand write
+			numString = numString + thousands + ' thousand'
+
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+		numString = numString + less_than_thousand(left)
+
+		numString
+	end
+
+	def less_than_billions (number)
+		numString = ""
+		left = number
+		write = left/1000000          # How many hundreds left to write out?
+		left  = left - write*1000000  # Subtract off those hundreds.
+
+		if write > 0
+			millions  = less_than_millions write
+			numString = numString + millions + ' million'
+		
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+
+		numString = numString + less_than_millions(left)
+
+		numString
+	end
+
+	def less_than_trillions (number)
+		numString = ""
+		
+		left = number
+		write = left/1000000000          # How many hundreds left to write out?
+		left  = left - write*1000000000  # Subtract off those hundreds.
+
+		if write > 0
+			billions  = less_than_billions write
+			numString = numString + billions + ' billion'
+		
+			if left > 0
+					numString = numString + ' '
+			end
+		end
+
+		numString = numString + less_than_billions(left)
+
+		numString
+	end
+end
\ No newline at end of file