ship sailing route is 120 kilometers long, and the distance between two adjacent ports is 20 kilometers. There are a total of ports in this route.
一条轮船航行路线全长120千米，相邻两个港口的距离都是20千米，这条路线一共有个港口．
<gadget id="calculator">120 / 20</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<result>7</result>