Casio FX-991EX Engineering/Scientific Calculator， Black<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>High Resolution Display to view more data like spreadsheets &amp; 4x4 matrix calculations</li><li>Natural Text book display - symbols and numbers appear just as they do in textbook</li><li>Numeric Integration/Differentiation</li><li>Simultaneous and Polynomial Solver</li><li>Solar Powered with Battery Backup (LR44 Button Cell Battery Included)</li></ul></div><img src="http://ecx.images-amazon.com/images/I/51ZHkUSA%2BTL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31VcZ3J3k0L.jpg" noproxy>