The Information Center is where you find out how to program in CL. The CL Reference section has a topic on Variables in CL commands that includes how to declare variables and how to change their values.
Examples include addition.
‘For a few dollars more…’
PGMENDPGMCouldn’t resist that one…-John Andersen
That could be shortened to just PGM. But note that it leaves out the “addition” part of the request. — Tom
Always search the IBM support site for documentation. In this case search for CL programmers reference manual… When you find one that helps you save the PDF document for future reference. You will need them as you grow as a programmer.