-- added Peter and Topher's solution --

002/original_spec/example_entry.rb

@@ -1,14 +1,59 @@
 class RomanNumeral
 
   def initialize( numeral_string )
+    @roman_string = numeral_string
   end
 
   def +( numeral_string )
-    "MMX"
+    self.to_I + numeral_string.to_I
   end
 
   def -( numeral_string )
-    "MCMXCVI"
+    self.to_I - numeral_string.to_I
+  end
+
+  def to_I
+    @roman_string.to_a.each do |letter|
+      if @roman_string.shorthand?
+        @longhand - Array( RomanNumeral.scratch_counts( letter ), "I" )
+      else
+        @longhand + Array( RomanNumeral.scratch_counts( letter ), "I" )
+      end
+      @roman_string = [ 1..( @roman_string.length - 1 ) ]
+    end
+  end
+
+  def shorthand?
+    @roman_string[ 1..( @roman_string.length - 1 ) ].detect{ |letter| RomanNumeral.letters.index( @roman_string[0] )
+  end
+
+  def self.scratch_counts( letter )
+    case letter
+    when 'I':
+      1
+    when 'V':
+      5
+    when 'X':
+      10
+    when 'L':
+      50
+    when 'C':
+      100
+    when 'D':
+      500
+    when 'M':
+      1000
+    else
+      raise "ERROR!! Wtf is that -- Greek?"
+    end
+  end
+
+  def self.letters
+    "MDCLXVI"
+  end
+
+  def self.has_shorthand?( letters )
+
   end
 end