To build a road, if you build 70 meters a day, you can finish it in 8 days; if you build 80 meters a day, how many days can you finish it? (Solution by proportional method)
修一条路，如果每天修70米，8天可以修完；如果每天修80米，几天可以修完？(用比例方法解)
<gadget id="calculator">70 * 8</gadget>
<output>560</output>

<gadget id="calculator">560 / 80</gadget>
<output>7</output>

<result>7</result>