HP F2240AA#ABA SmartCalc 300s Scientific Calculator Ideal for - General math, pre-algebra/algebra, trigonometry, statistics, geometry, biology, chemistry, physics, and earth sciences&gt;BR&gt;Features - Entry-system logic - Algebraic Math functions - Sign change, +, /, -, x, =, square root, %, fractions, mixed numerals, fraction to decimal conversion, sexagesimal (degree, minute, second), variables (A, B, C, D, X, Y), trigonomic, inverse trigonometric, exponential, logarithmic, powers, factorial (!), absolute value (Abs), random number, rounding, polar-rectangular conversions, permutation and combination. Added features - Navigation pad, memory calculations, snap-on protective cover. Power System - Solar powered with 1 x LR44 battery as back-up. Auto-power off 5 to 10 minutes.