diff --git a/README.md b/README.md
index 22c75b0..ae84d69 100644
--- a/README.md
+++ b/README.md
@@ -32,4 +32,8 @@
 |  |
 | ------- |
 | [0001-two-sum](https://github.com/gogumaC/algorithm/tree/master/0001-two-sum) |
+## Math
+|  |
+| ------- |
+| [0009-palindrome-number](https://github.com/gogumaC/algorithm/tree/master/0009-palindrome-number) |
 <!---LeetCode Topics End-->
\ No newline at end of file