A worker has to make 504 parts, and he makes 120 parts in 5 days. At this speed, how many days will it take to make the rest? (Solve with ratio)
某工人要做504个零件，他5天做了120个，照这样的速度，余下的还要做多少天？(用比例解)
<gadget id="calculator">504 - 120</gadget>
<output>384</output>

<gadget id="calculator">120 / 5</gadget>
<output>24</output>

<gadget id="calculator">384 / 24</gadget>
<output>16</output>

<result>16</result>