Adding machine

A desk adding machine, in the browser

Before spreadsheets, accountants totted up columns on adding machines that printed every entry on a paper roll. The tape was the point: you could check each figure, write a note next to it and staple it to the invoice. This page works the same way. Type or paste numbers, one per line, and the tape prints each entry with the running total beside it.

Copy the tape as text, share it as a link that reopens the same entries, or print it.

Operators and percentages

A line on its own is added. Start a line with − to subtract, × (or * or x) to multiply and ÷ (or /) to divide. Each line acts on the total so far, so 10, + 5, × 2 gives 30: there is no operator precedence, exactly like a mechanical machine.

+15% adds 15% of the running total and −10% takes 10% off. A line with only = prints a subtotal, which is handy for separating groups such as rent and bills.

Labels and pasted columns

Anything after the number is kept as a label: 86.40 groceries prints as + 86.40 groceries. Numbers can use thousands commas (1,250.00) and shortcuts like 2.5k. Pasting a column from a spreadsheet or a bank statement adds every line at once, and lines that are not numbers are flagged rather than silently dropped.