diff --git a/README.md b/README.md
index 0a94ccb..8f9996c 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 1 + 98 = 99
 64 * 11 = 704
 83 + 17 = 100
+37 - 58 = -21