PURPOSE: To accurately totalize cash without using any expensive equipment by connecting plural cash processors in series and a higher order processor adds its own totalization amount to the total response of lower order processors and successively transmits the added amount to the higher order processors by a totalizing instruction given from the processor of the highest order.

CONSTITUTION: The totalizers 5a, 5b... of cash processors are connected to each other via a serial interface. When the totalization data are retrieved by the totalizer 5a, each of other totalizers requests its adjacent totalizer to report the totalization data. The 2nd totalizer 5b requests the totalizer 5c to report its totalization data against the request given from the totalizer 5a to add together with the totalizartion data of the totalizers 5c and 5d. Receiving the totalization data of the totalilzer 5d of the lowest order, the totalizer 5c adds its own totalization data to the received totalization data and reports this added data to the totalizer 5b. In such a way, all received totalization data are finally sent to the totalizer 5a of the highest order. Thus the totalizer 5a adds its own totalization data to the received totalization data.