The highway from Shanghai to Nanjing is 304 kilometers long. Uncle Wang drove 152 kilometers from Shanghai in two hours. At this speed, how many hours will it take to reach Nanjing?
上海到南京的公路线长304千米，王叔叔驾车从上海出发两小时行了152千米，照这样的速度，到南京还要几小时？
<gadget id="calculator">152 / 2</gadget>
<output>76</output>

<gadget id="calculator">304 / 76</gadget>
<output>4</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<result>2</result>