diff --git a/README.md b/README.md
index 9073e77..97b0bcc 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 4 + 61 = 65
 2 - 54 = -52
 75 - 59 = 16
+13 + 18 = 31