Sharp Electronics EL-W516XBSL Scientific CalculatorSharp Electronics' Commitment to InnovationSharp Electronics strives to help you create a balance between work and personal time. Our products enhance life at work, at home, and everywhere in between. Sharp is dedicated to improving lives through the use of advanced technology and a commitment to innovation, quality, value and design.Superior FunctionalityThe EL-W516XBSL is a fully-functional, high quality scientific calculator that performs over 530 advanced scientific and mathematical functions. It features WriteView Technology that allows students to view formulas in the exact order they appear in their textbook.  It also utilizes a large, easy to read a 4-line display and a Playback feature so you can edit formulas easily. For quick use of your desired functions, there are four programmable keys.  Plus, the equation solver gives you the ability to solve three equations simultaneously!  The EL-W516XBSL makes solving difficult scientific equations a piece of cake!Perfect for StudentsAdvanced technology and engineering gives you the pin-point accuracy you expect from Sharp Electronics. It is ideal for students studying general math, algebra, geometry, trigonometry, statistics, biology, chemistry, and general science.Features556 Scientific Functions - Statistical, Trigonometric, and Other FunctionsLarge Display - 4-Line, 16-Digit LCD Display WriteView Technology - Formulas Displayed as Written in TextbooksPlayback - To Edit and Make Changes to Formulas EasilyModes - Normal, Stat, Drill, Complex, Matrix, List, EquationFour Programmable Keys - For Quick use of User Desired FunctionsEquation Solver - Ability to Solve Three Simultaneous EquationsScientific Functions:sin, cos, tan, sin-1, cos-1, tan-1Log, In, 10x, eXLog_axsinh, cosh, tanh, sinh-1, cosh-1, tanh-1n!nCr, cPrRANDOMDEG, RAD, GRAD [DRG]-> r8, ->xy>DEG, >RAD,>GRAD [DRG]abcEL-501XBWH EL-501XBGR EL-531XBWH EL-531XBGR EL-520XBWHEL-W535XBSLEL-506XBWHEL-W516XBSLPhysical Dimensions WxHXD (Inches) 3.1x5.7x.5 3.1x5.7x.5 3.1x6.1x.5 3.1x6.1x.5 3.1x6.1x.5 3.1x6.4x.6 3.1x6.1x.5 3.1x6.4x.6 Weight (ounces) 2.6 2.6 3.4 3.4 3.4 4.1 3.4 3.6 Power Battery only Battery only Battery only Battery only Twin Power(Solar+battery) Battery only Twin Power(Solar+battery) Twin Power(Solar+battery) Display Display 1-Line 1-Line 2-Line 2-Line 2-Line 4-Line 2-Line 4-Line Exponent symbol(x10) No No Yes Yes Yes (E) Yes (E) Yes Yes (E) Display "=" (on result display) No No Yes Yes Yes Yes Yes Yes WriteView No No No No No Yes No Yes Basic Features Number of functions 131 131 272 272 419 335 469 556 Editing Equation No No Yes Yes Yes Yes Yes Yes Playback Equation No No Yes Yes Yes Yes Yes Yes Multi-line playback No No No No No Yes No Yes Number of Memory 1 1 9 9 9 9 9 9 Last Answer Memory No No Yes Yes Yes Yes Yes Yes Statistics Data Store No No Yes Yes Yes Yes Yes Yes