Sharp Electronics EL520WBBK 12-Digit Scientific Handheld Calculator Direct Algebraic Logic allows students to enter the elements of an expression in the exact order they appear in the textbook Extra large 12-digit, 2-line display  one line equation and one line numeric Multi-Line Playback allows students to playback expressions and substitute new numeric values Differential and integral calculus functions Hard case protects case for long-term durability