Today I installed scala using “apt-get install scala” and confirmed the scala jar files are located in /usr/share/java
You should be able to set your SCALA_HOME to /usr/share/java and have it all work. I assume you want to use NetBeans so you will need to set SCALA_HOME in your .profile (or .bash_profile) rather than in your .bashrc because NetBeans won’t see any variables set in your .bashrc unless you start it from the command line
$ find / -maxdepth 6 -iname \*scala\*jar 2> /dev/null
/usr/share/java/scala-dbc.jar
/usr/share/java/scala-partest.jar
/usr/share/java/scala-partest-2.9.1.jar
/usr/share/java/scala-dbc-2.9.1.jar
/usr/share/java/scalacheck.jar
/usr/share/java/scalap.jar
/usr/share/java/scala-library-2.9.1.jar
/usr/share/java/scala-compiler-2.9.1.jar
/usr/share/java/scala-library.jar
/usr/share/java/scalacheck-2.9.1.jar
/usr/share/java/scala-compiler.jar
/usr/share/java/scala-swing-2.9.1.jar
/usr/share/java/scalap-2.9.1.jar
/usr/share/java/scala-swing.jar