diff --git a/README.md b/README.md
index 40a07c2..13cba42 100644
--- a/README.md
+++ b/README.md
@@ -42,3 +42,4 @@
 94 + 93 = 187
 58 - 77 = -19
 8 - 41 = -33
+68 - 37 = 31