A calculator with very small screen footprint but lots of power! Just type in any expression, like "2+3.9/7.1-3 sqr 5", and hit Enter; then modify it and evaluate again at will, without re-entering everything. 18 digits of precision, 30 functions, 12 memories (variables), fractions, unit conversion, adjustable display format and precision, deg/min/sec, save and restore, on-line help; this program is loaded!