SUB-TOTAL DISCOUNTING METHOD

PURPOSE:To count the tax more correctly without performing complicated calculation compared with the conventional method. CONSTITUTION:By using a sales data processor 1, when a tax rate is one kind, the tax rate is multiplied by the sub-total amount after discount, a tax amount is calculated, the calculated tax amount is added to the sub-total amount after the discount and the payment amount of a customer is calculated. When the tax rate is not one kind, the tax rate is multiplied by the price of the individual merchandise, the tax amount is calculated, the accumulating totals of the tax amount are added to the sub-total amount after the discount and the payment amount of the customer is calculated.