I am reading a 360-page children's book. I have read 80 pages in the first three days, and the rest are 40 pages a day on average. How many days will it take to finish reading?
我正在读一本360页的儿童读物，前三天已经读了80页，剩下的平均每天读40页，共需几天才能读完？
<gadget id="calculator">360 - 80</gadget>
<output>280</output>

<gadget id="calculator">280 / 40</gadget>
<output>7</output>

<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<result>10</result>