An engineering team wants to repair a 7.2km long road, and completed 3.2km in the first 4 days. According to this calculation, how many days will it take to complete? (Solution with proportional knowledge)
一工程队要修一条长7.2km的公路，前4天完成了3.2km，照这样计算，剩下的还要多少天完成？(用比例知识解)
<gadget id="calculator">7.2 - 3.2</gadget>
<output>4</output>

<gadget id="calculator">3.2 / 4</gadget>
<output>0.8</output>

<gadget id="calculator">4 / 0.8</gadget>
<output>5</output>

<result>5</result>