1 files changed, 4 insertions, 0 deletions

diff --git a/src/unitnumber.cpp b/src/unitnumber.cpp
index d213ed7..c316d4b 100644
--- a/src/unitnumber.cpp
+++ b/src/unitnumber.cpp
@@ -89,6 +89,10 @@ void UnitNumber::number1()
     mathTest("1000902491523000321", *, "3004392012498000700",

             "3007103450821050020096034077958224700");

 

+    mathTest("-4", -, "5", "-9");

+    mathTest("-4", -, "-5", "1");

+    mathTest("-4", +, "5", "1");

+    mathTest("5", +, "-4", "1");

     mathTest("-872", +, "123", "-749");

     mathTest("728", +, "-51", "677");

     mathTest("44", +, "-55", "-11");