Texas Instruments TI-503SV Pocket Calculator, 8-Digit LCDPocket-size calculator with SuperView display provides easy, on-the-spot answers. Well-spaced rubber keys. Automatic power down feature conserves battery life. Change sign (+/-) key simplifies entry of negative numbers. Last answer function. Power Source(s): Battery; Display Notation: Numeric; Number of Display Digits: 8; Memory: 3-Key.