Each of the hand-held calculator logic systems found on the market today is introduced, along with some of the advantages and disadvantages of each. The systems reviewed are: arithmetic logic, algebraic logic-no hierarchy, algebraic operating system, and reverse polish notation. (MP)

The four-color theorem stating that any map in a plane can be colored using no more than four colors represents a problem suitable for the liberal arts student. Presented is an algorithm for coloring familiar maps through the temporary removal of states bordering three or fewer states. (MDH)