Abstract: An electronic calculator having a graph display function which displays a graph of a desired function on a liquid-crystal display screen, within a designated range, input from a keyboard. The electronic calculator can change the range using a predetermined point or range on the screen as the center, thus enlarging or reducing the displayed graph to a desired magnification.

Abstract: An electronic calculator has a program calculation function. The calculator also includes a key for designating substitution of numeral data for variables, a key for designating a variable, and a key for representing an interval of variables in addition to normal numeric keys. When numeral data (e.g., 10) is to be substituted for variables (e.g., A to D and H to K) among certain program variables, an operator designates numeral data "10", variables A to D and H to K with the keys. A control section then starts a substituting operation by storing the numeral data "10" in memory areas of a variable memory defined by addresses corresponding to the variables A to D and H to K. Thus, the numeral data "10" is substituted for the variables A to D and H TO K.

Abstract: In an intelligent card, a keyboard has numeric keys for entering identification information and a collation execution key. A solar cell, a display device and an IC chip for performing arithmetic operations and card identification are incorporated in a case. The IC chip includes a nonvolatile memory for storing predetermined identification information. The predetermined identification information is compared with the input identification information entered at the keyboard upon operation of the key, thereby performing card identification.