10-digit all-purpose scientific calculator offers 144 built-in mathematical functions including basic scientific, exponential and trigonometric. Provides six levels of parentheses, single variable statistical and fraction calculations, polar-rectangular conversions. Includes mean, standard deviation, permutations and combinations, backspace key to fix entry mistakes. Calculator is permitted on college entrance examination boards such as SAT and PSAT/NMSQT. Integrated slide-on hard case protects calculator.