diff --git a/README.md b/README.md
index d96d3bd..f1fdd1a 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 73 / 2 = 36
 67 + 50 = 117
 14 / 2 = 7
+66 - 57 = 9