diff --git a/binary_search_tree/tree.py b/binary_search_tree/tree.py
index cdd5abc..9f696e3 100644
--- a/binary_search_tree/tree.py
+++ b/binary_search_tree/tree.py
@@ -1,5 +1,5 @@
 class TreeNode:
-    def __init__(self, key, val = None):
+    def __init__(self, key, val=None):
         if val == None:
             val = key
 
@@ -7,53 +7,139 @@ def __init__(self, key, val = None):
         self.value = val
         self.left = None
         self.right = None
-        
+
+    def add(self, key, value=None):
+        if key < self.key:
+            if self.left is None:
+                self.left = TreeNode(key, value)
+                return self.left
+            return self.left.add(key, value)
+        else:
+            if self.right is None:
+                self.right = TreeNode(key, value)
+                return self.right
+            return self.right.add(key, value)
+
+    def inorder(self, list):
+        if self.left is not None:
+            self.left.inorder(list)
+
+        list.append({
+            "key": self.key,
+            "value": self.value
+        })
+
+        if self.right is not None:
+            self.right.inorder(list)
+
+    def preorder(self, list):
+        list.append({
+            "key": self.key,
+            "value": self.value
+        })
+
+        if self.left is not None:
+            self.left.preorder(list)
+
+        if self.right is not None:
+            self.right.preorder(list)
+
+    def postorder(self, list):
+        if self.left is not None:
+            self.left.postorder(list)
+
+        if self.right is not None:
+            self.right.postorder(list)
+
+        list.append({
+            "key": self.key,
+            "value": self.value
+        })
+
+    def height(self):
+        if self.left is None:
+            leftHeight = 0
+        else:
+            leftHeight = self.left.height()
+
+        if self.right is None:
+            rightHeight = 0
+        else:
+            rightHeight = self.right.height()
+
+        return 1 + max(leftHeight, rightHeight)
 
 
 class Tree:
     def __init__(self):
         self.root = None
 
-    # Time Complexity: 
-    # Space Complexity: 
-    def add(self, key, value = None):
-        pass
+    # Time Complexity:
+    # Space Complexity:
+    def add(self, key, value=None):
+        if self.root is None:
+            self.root = TreeNode(key, value)
+            return self.root
+        else:
+            return self.root.add(key, value)
+
+    def find_helper(self, current, key):
+        if current == None:
+            return None
+        elif current.key == key:
+            return current.value
+        elif key < current.key:
+            return self.find_helper(current.left, key)
+
+        return self.find_helper(current.right, key)
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: o(1)
+    # Space Complexity:o(n)
     def find(self, key):
-        pass
+        return self.find_helper(self.root, key)
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity:  o(1)
+    # Space Complexity: o(1)
     def inorder(self):
-        pass
+        list = []
+        if self.root is not None:
+            self.root.inorder(list)
+        return list
+
+    # Time Complexity: o(n)
+    # Space Complexity:0(n)
 
-    # Time Complexity: 
-    # Space Complexity:     
     def preorder(self):
-        pass
+        list = []
+        if self.root is not None:
+            self.root.preorder(list)
+        return list
 
-    # Time Complexity: 
-    # Space Complexity:     
+    # Time Complexity: 0(log n)
+    # Space Complexity:o(1)
     def postorder(self):
-        pass
+        list = []
+        if self.root is not None:
+            self.root.postorder(list)
+        return list
 
-    # Time Complexity: 
-    # Space Complexity:     
+    # Time Complexity: o(n)
+    # Space Complexity:0(n)
     def height(self):
-        pass
+        if self.root is None:
+            return 0
+        return self.root.height()
 
 
 #   # Optional Method
-#   # Time Complexity: 
-#   # Space Complexity: 
+#   # Time Complexity:
+#   # Space Complexity:
+
     def bfs(self):
         pass
 
-        
-
 
 #   # Useful for printing
+
     def to_s(self):
         return f"{self.inorder()}"
diff --git a/tests/__pycache__/__init__.cpython-39.pyc b/tests/__pycache__/__init__.cpython-39.pyc
index aa55c2e..6783307 100644
Binary files a/tests/__pycache__/__init__.cpython-39.pyc and b/tests/__pycache__/__init__.cpython-39.pyc differ