The ultimate graphing calculator for surveying, engineering, math and science professionals and students. 2,300 built-in functions. Powerful SD card slot allows you to format your card right in the calculator and expand memory. Choose RPN, textbook or algebraic entry and customize data with four font sizes and styles. Enhanced HP keypad with redefinable keyboard and menu keys for reduced keying errors. Calculate advanced expressions and view solutions in 2-D or 3-D graphical representation on high-contrast display. Power Source(s): Battery; Display Notation: Numeric; Number of Display Digits: N/A; Display Characters x Display Lines: 131 x 80 pixels.