diff --git a/lib/fibonacci.rb b/lib/fibonacci.rb
index 7465c25..483a00d 100644
--- a/lib/fibonacci.rb
+++ b/lib/fibonacci.rb
@@ -1,8 +1,14 @@
 # Improved Fibonacci
 
-# Time Complexity - ?
-# Space Complexity - ?  (should be O(n))
+# Time Complexity - O(n!)
+# Space Complexity O(n) 
 # Hint, you may want a recursive helper method
 def fibonacci(n)
- 
+  if n < 0
+    raise ArgumentError, "Invalid number"
+  elsif n == 0 || n == 1
+    return n
+  else
+    return fibonacci(n - 2) + fibonacci(n - 1)
+  end 
 end
diff --git a/lib/super_digit.rb b/lib/super_digit.rb
index 33e367f..3aa244c 100644
--- a/lib/super_digit.rb
+++ b/lib/super_digit.rb
@@ -1,10 +1,30 @@
 # Superdigit
 
-# Time Complexity - ?
-# Space Complexity - ?
-def super_digit(n)
-   
+# Time Complexity - O(n)
+# Space Complexity - O(n)
+def super_digit(x)
+   if x < 10
+    return x
+  elsif
+    sum = integer_calcuation(x)
+    super_digit(sum)
+  end 
 end
+
+def integer_calcuation(x)
+  
+  digit_array = x.to_s.split('')
+
+  sum = 0
+
+  digit_array.each do |element|
+    sum += element.to_i
+  end 
+
+  return sum
+end 
+
+
   
 
 # Time Complexity - ?
diff --git a/test/super_digit_test.rb b/test/super_digit_test.rb
index 60da3a1..20973f1 100644
--- a/test/super_digit_test.rb
+++ b/test/super_digit_test.rb
@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "super_digit" do
+describe "super_digit" do
   it "will return 2 for super_digit(9875)" do
     # Act
     answer = super_digit(9875)
@@ -33,7 +33,7 @@
     expect(answer).must_equal 6
   end
 
-  describe "refined superdigit" do 
+  xdescribe "refined superdigit" do 
     it "will return 1 for n = 1 and k = 1" do
       # Act
       answer = refined_super_digit(1, 1)