Having worked with a patent attorney in the past, I can give you specific wording examples. The software patents I've seen stated the claims in three different ways, to take advantage of different patentable areas: "A method for $foo", "A system for $foo" (as in a computer system), and "A computer program product for $foo".

Those same software patents also included, in addition to all the illustrations of the algorithm, a diagram of a stack of computer discs capable of containing the program, in order to demonstrate that (at least in some embodiments) the patent actually covered a physical thing rather than an algorithm.