Calcute is a free, compact, capable tape calculator. Compact single-line mode
or flexible multi-line editor to edit past work, recalculate, cut and paste
on the tape, save to file, restore. This expression evaluator processes
complex expressions like -ln(1+2) * 3% + sin(4 5\6)^7 and allows exact
rational values like 2 1\3 instead of 2. (in Education)