diff --git a/src/my_project/interviews/top_150_questions_round_16/palindrome.py b/src/my_project/interviews/top_150_questions_round_16/palindrome_number.py
similarity index 100%
rename from src/my_project/interviews/top_150_questions_round_16/palindrome.py
rename to src/my_project/interviews/top_150_questions_round_16/palindrome_number.py
diff --git a/src/my_project/interviews/top_150_questions_round_16/plus_one.py b/src/my_project/interviews/top_150_questions_round_16/plus_one.py
new file mode 100644
index 00000000..daed75a1
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_16/plus_one.py
@@ -0,0 +1,20 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def plusOne(self, digits: List[int]) -> List[int]:
+
+        len_digits = len(digits)
+
+        for i in range(len_digits-1,-1,-1):
+
+            if digits[i] != 9:
+                digits[i] += 1
+                break 
+            else:
+                digits[i] = 0
+
+        if digits[0] == 0:
+            return [1] + digits
+        else: 
+            return digits
\ No newline at end of file
diff --git a/tests/test_150_questions_round_16/test_palindrome_round_16.py b/tests/test_150_questions_round_16/test_palindrome_number_round_16.py
similarity index 92%
rename from tests/test_150_questions_round_16/test_palindrome_round_16.py
rename to tests/test_150_questions_round_16/test_palindrome_number_round_16.py
index 46345b36..468bcd77 100644
--- a/tests/test_150_questions_round_16/test_palindrome_round_16.py
+++ b/tests/test_150_questions_round_16/test_palindrome_number_round_16.py
@@ -1,6 +1,6 @@
 import unittest
 from src.my_project.interviews.top_150_questions_round_16\
-.palindrome import Solution
+.palindrome_number import Solution
 
 class PalindromeNumberTestCase(unittest.TestCase):
 
diff --git a/tests/test_150_questions_round_16/test_plus_one_round_16.py b/tests/test_150_questions_round_16/test_plus_one_round_16.py
new file mode 100644
index 00000000..e0fe76b4
--- /dev/null
+++ b/tests/test_150_questions_round_16/test_plus_one_round_16.py
@@ -0,0 +1,19 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_16\
+.plus_one import Solution
+
+class PlusOneTestCase(unittest.TestCase):
+
+    def test_leading_one(self):
+        solution = Solution()
+        output = solution.plusOne(digits=[9])
+        target = [1, 0] 
+        for k, v in enumerate(target):
+            self.assertEqual(v, output[k])
+
+    def test_no_leading_one(self):
+        solution = Solution()
+        output = solution.plusOne(digits=[1, 2])
+        target = [1, 3] 
+        for k, v in enumerate(target):
+            self.assertEqual(v, output[k])
\ No newline at end of file