diff --git a/src/TraversalPractice.java b/src/TraversalPractice.java
index 2aa9b81..b1ea973 100644
--- a/src/TraversalPractice.java
+++ b/src/TraversalPractice.java
@@ -10,7 +10,15 @@ public class TraversalPractice {
      * @param node the root of the tree
      */
     public static void printNegativeNodesInOrder(TreeNode node) {
+        if (node == null) return;
 
+        printNegativeNodesInOrder(node.left);
+
+        if (node.data < 0 ) {
+            System.out.println(node.data);
+        }
+
+        printNegativeNodesInOrder(node.right);
     }
     
     /**
@@ -37,6 +45,12 @@ public static void printNegativeNodesInOrder(TreeNode node) {
      * @return the sum of the leaf node values
      */
     public static int sumLeafNodes(TreeNode node) {
-        return -1;
+        if (node == null) return 0;
+
+        if (node.left == null && node.right == null) {
+            return node.data;
+        }
+
+        return sumLeafNodes(node.left) + sumLeafNodes(node.right);
     }
 }