When calculator is launched from jar there is no button to close the app.
To reproduce download ga-samples from http://jre.us.oracle.com/java/re/javafx/8.0/promoted/latest/bundles/windows-x64/.
To reproduce download ga-samples from http://jre.us.oracle.com/java/re/javafx/8.0/promoted/latest/bundles/windows-x64/.