diff --git a/README.md b/README.md
index e671adb..1901f9c 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 11 - 20 = -9
 11 + 17 = 28
 53 / 3 = 17
+60 - 21 = 39