A 3,200-meter-long road was built, and 800 meters were repaired in 4 days. According to this calculation, how many days are left to repair? (Solve with ratio)
修一条长3200米的路，4天修了800米，照这样计算，余下的还要修多少天？(用比例解)
<gadget id="calculator">3_200 - 800</gadget>
<output>2_400</output>

<gadget id="calculator">800 / 4</gadget>
<output>200</output>

<gadget id="calculator">2_400 / 200</gadget>
<output>12</output>

<result>12</result>