diff --git a/lib/tree.rb b/lib/tree.rb
index c0d4b51..b710d56 100644
--- a/lib/tree.rb
+++ b/lib/tree.rb
@@ -18,40 +18,139 @@ def initialize
 
   # Time Complexity: 
   # Space Complexity: 
-  def add(key, value)
-    raise NotImplementedError
+  def add(key, value = 0)
+    # there may or may not be a root
+    # if there's no root then the key/value will be the new root
+    # otherwise check to see if value is bigger or smaller than the root value
+    # initialize new node with the key and value
+    # check if it's smaller or larger and if it's the last node of the branch
+    # if it's the last node then add it after that node
+    input = TreeNode.new(key,value)
+    if @root == nil 
+      @root = input
+      return
+    else here = @root
+    end
+    while here != nil
+      if input.key < here.key
+        if here.left != nil
+          here = here.left
+        else here.left = input
+          return
+        end
+      else input.key > here.key
+        if here.right != nil
+          here = here.right
+        else here.right = input
+          return
+        end
+      end
+    end  
   end
 
   # Time Complexity: 
   # Space Complexity: 
   def find(key)
-    raise NotImplementedError
+    if @root.nil?
+      return nil
+    end
+    here = @root
+    while here != nil
+      if here.key == key
+        return here.value
+      elsif key < here.key
+          here = here.left
+      elsif key > here.key
+          here = here.right
+      end
+    end
+    return nil
   end
 
   # Time Complexity: 
   # Space Complexity: 
   def inorder
-    raise NotImplementedError
+    values = []
+    if @root.nil?
+      return values
+    end
+    return inorder_helper(@root, values)
   end
 
+  def inorder_helper(here, values)
+    if here.nil?
+      return values
+    end
+
+    inorder_helper(here.left, values)
+    values.push({:key=>here.key, :value=>here.value})
+    inorder_helper(here.right, values)
+    return values
+  end
+
+
   # Time Complexity: 
   # Space Complexity: 
   def preorder
-    raise NotImplementedError
+    values = []
+    if @root.nil?
+      return values
+    end
+    return preorder_helper(@root, values)
+  end
+
+  def preorder_helper(here, values)
+    if here.nil?
+      return values
+    end
+    
+    values.push({:key=>here.key, :value=>here.value})
+    preorder_helper(here.left, values)
+    preorder_helper(here.right, values)
+    
+    return values
   end
 
   # Time Complexity: 
   # Space Complexity: 
   def postorder
-    raise NotImplementedError
+    values = []
+    if @root.nil?
+      return values
+    end
+    return postorder_helper(@root, values)
+  end
+
+  def postorder_helper(here, values)
+    if here.nil?
+      return values
+    end
+
+    postorder_helper(here.left, values)
+    postorder_helper(here.right, values)
+    values.push({:key=>here.key, :value=>here.value})
+    return values
   end
 
   # Time Complexity: 
   # Space Complexity: 
   def height
-    raise NotImplementedError
+    height = 0
+    if @root.nil?
+      return height
+    end
+    return height_helper(@root)
+  end
+  
+  def height_helper(here)
+    if here.nil?
+      return 0
+    end
+    return 1 + [height_helper(here.left), height_helper(here.right)].max
   end
 
+
+
   # Optional Method
   # Time Complexity: 
   # Space Complexity: