Calculate - the
etymology comes from the latin word for pebbles.
In Roman times, man-powered taxis would have a
bingo-like device that rolls with the axis of the wheel, depositing a pebble for each rotation into a basket below. At the end of the ride, the driver/runner would calculate the pebbles that got dropped into the basket,
Book Spine Calculator thus figuring out the distance, and the cost, of the ride.