The store has newly introduced "natural" mineral water. The purchase price is 24 yuan per box, and the selling price is 36 yuan per box. Last month, 720 boxes were sold. Please count the only "natural" mineral water in the store last month. One item, how much did you earn?
商店新进来了"天然"矿泉水，进价为每箱24元，售价为每箱36元，上个月卖出了720箱，请你算一算上个月商店仅"天然"矿泉水一项，赚了多少钱？
<gadget id="calculator">36 - 24</gadget>
<output>12</output>

<gadget id="calculator">12 * 720</gadget>
<output>8_640</output>

<result>8_640</result>