diff --git a/README.md b/README.md
index 9eb015b..b4f16fd 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 87 - 98 = -11
 93 * 53 = 4929
 84 + 14 = 98
+6 + 15 = 21