diff --git a/README.md b/README.md
index 90471c4..cb2d947 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 32 / 1 = 32
 73 * 90 = 6570
 35 / 4 = 8
+5 - 20 = -15