Tallette: Tape Calculator

A paper-tape calculator: type amounts down the tape as on an adding machine, give each line a comment, and fix any line at any time. The totals below it follow at once. TYPE AS YOU WOULD SAY IT • 12.50+ adds, −7.20 lunch subtracts with a comment, 3×4= multiplies, +19% tax adds tax, 15% takes a percentage. • Subtotals, totals and grand totals, like an adding machine's, and new sections for each part of a job. • Your region's number format, with a decimal point or comma, and forgiving when you type the other one. EVERY LINE STAYS EDITABLE Change an amount ten lines up and everything below it is worked out again. Comments say what each number is; a #tag in a comment totals lines by category: food, rent, travel. EXACT, TO THE LAST CENT Tallette counts in decimal, never in binary floating point: 0.10 + 0.20 is exactly 0.30. Results keep 34 significant digits and round half up; dividing by…