Decision Tree Using the SOS, EraTech sends out invoices monthly and will gi,e discounts if payments are made within 10 days, The discount policy is as follows: If the amount of the order for computer supplies is greater than $1,000, subtract 4 percent for the order; if the amount is between $500 and $1,000, subtract a 2 percent discount; if the amount is less than $500, a discount is not applicable. All orders made via the Web will automatically receive an extra 5 percent discount.