Abstract: A pocket calculator includes a casing having on its front face numeric and function keys and a numeric first liquid crystal display (LCD) and a message second LCD. Housed in the casing is a calculator network module housing and a first battery connected through a key operated switch contained in the network to energize the network and actuate the first LCD. An inverter IC integrated circuit and second battery are housed in the casing and actuate the second LCD, the battery being connected to the inverter input through a transistor switch rendered conductive in response to the energization of the calculator network. Alternatively, a message third LCD provided in which the message is devisualized upon the application of a voltage thereto with the energization of the computer. The second and third LCDs may be a single common unit with the faces of a section of a common LCD being coated with light polarizing layers which are optically mutually perpendicular.