diff --git a/README.md b/README.md
index 6ad5d33..61f49db 100644
--- a/README.md
+++ b/README.md
@@ -41,3 +41,4 @@
 87 + 4 = 91
 48 / 8 = 6
 50 + 24 = 74
+39 - 19 = 20