A machinery factory processes a batch of parts. The original plan is to process 210 parts per day, and the task is completed in 18 days. In fact, 30 more parts are processed every day, so how many days are actually required to complete the processing tasks of this batch of parts?
某机械厂加工一批零件，原计划每天加工210个，18天完成任务．实际每天多加工30个，那么实际多少天完成这批零件的加工任务？
<gadget id="calculator">210 + 30</gadget>
<output>240</output>

<gadget id="calculator">18 / 240</gadget>
<output>3/40 = around 0.075</output>

<gadget id="calculator">210 * (3/40)</gadget>
<output>63/4 = around 15.75</output>

<result>63/4 = around 15.75</result>