Master Wang has to process 900 parts, and processed 250 parts in the first 5 days. With this efficiency, how many days will it take to complete the task?
王师傅要加工900个零件，前5天加工了250个．照这样的效率，还要多少天完成任务？
<gadget id="calculator">900 - 250</gadget>
<output>650</output>

<gadget id="calculator">250 / 5</gadget>
<output>50</output>

<gadget id="calculator">650 / 50</gadget>
<output>13</output>

<result>13</result>