diff --git a/README.md b/README.md
index a4adbc5..4802370 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 26 - 39 = -13
 88 + 7 = 95
 37 / 6 = 6
+31 - 99 = -68