There are 20 rows of empty seats in the school auditorium. There are 140 students in the third grade. The teacher arranges for every 10 people to sit in a row. How many rows of seats are there in the auditorium?
学校礼堂有20排空白的座位，三年级有140人，老师安排每10人坐一排，礼堂里还空着几排座位？
<gadget id="calculator">140 / 10</gadget>
<output>14</output>

<gadget id="calculator">20 - 14</gadget>
<output>6</output>

<result>6</result>