Receipt slips with sums drift down three lanes toward the counter. Type a slip's answer on the number pad (or your keyboard) and it clears as soon as the answer matches; the check button submits, the arrow deletes. A slip that reaches the counter costs one of three lives and sweeps the shelf. Sums start as small additions up to ten, then bigger sums, take-aways, times tables up to 5 × 5, cafe bills that add the prices of two or three items, and two-digit numbers, while slips fall faster and more of them share the shelf. A golden tip slip clears every slip on screen. Clearing slips in a row raises the combo multiplier. Challenge a friend to the same run with a link.