The afforestation team planted 200 trees in 4 days, and another 400 trees will be planted. At this working speed, how many days will it take to complete the task?
绿化队4天种树200棵，还要种400棵，照这样的工作速度，完成任务共需多少天？
<gadget id="calculator">200 + 400</gadget>
<output>600</output>

<gadget id="calculator">200 / 4</gadget>
<output>50</output>

<gadget id="calculator">600 / 50</gadget>
<output>12</output>

<result>12</result>