DEVICE FOR PERFORMING FOUR ARITHMETICAL OPERATIONS BY USING NAVIGATION KEY IN PORTABLE TERMINAL AND METHOD THEREFOR - THE METHOD COMPRISES STEPS OF DECIDING WHETHER INPUT OF NAVIGATION KEY EXISTS CONTINUOUSLY AFTER INPUT OF NUMBER KEY, AND THEN CONVERTING INTO ELECTRONIC CALCULATOR MODE BY THE NAVIGATION KEY

摘要

PURPOSE: A method for performing four arithmetical operations by using a navigation key in a portable terminal is provided to decide whether the input of a navigation key exists continuously after the input of a number key, and to convert into an electronic calculator mode by the navigation key, thereby simply performing an electronic calculation by the converted mode. CONSTITUTION: A user inputs number keys(500). A portable terminal decides whether one of the number keys is continuously inputted during a certain time(502). If not, the portable terminal decides whether a navigation key is operated after the number keys(506). If so, the portable terminal selects an electronic calculator mode from a mode selector(508). The portable terminal performs four arithmetical operations according to a given rule by using information inputted after the electronic calculator mode and previously inputted numbers(516).