To build a 3,000-meter-long road, 1,600 meters have been built in the first four days. According to this calculation, how many days will it take to complete the road?
修一条3000米长的公路，前四天已修1600米，照这样计算，修完这条路还需要多少天？
<gadget id="calculator">3_000 - 1_600</gadget>
<output>1_400</output>

<gadget id="calculator">1_600 / 4</gadget>
<output>400</output>

<gadget id="calculator">1_400 / 400</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>