Mom spent 840 yuan to buy 7 boxes of pens, 8 pens in each box, how much is each pen on average?
妈妈花840元买了7盒钢笔，每盒8支，平均每支多少钱？
<gadget id="calculator">840 / 7 / 8</gadget>
<output>15</output>

<result>15</result>