diff --git a/README.md b/README.md
index 2c6a75d..a774946 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 36 * 63 = 2268
 29 + 98 = 127
 40 + 53 = 93
+91 - 71 = 20