A factory makes a batch of parts; originally planned to make 200 parts per day, but actually made 50 more parts per day, and the result was completed 8 days ahead of schedule. How many days did it actually take?
某工厂做一批零件；原计划每天做200个，实际每天多做50个，结果提前了8天完成，实际用了多少天？
<gadget id="calculator">1 / 200</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">200 + 50</gadget>
<output>250</output>

<gadget id="calculator">1 / 250</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">(1/200) - (1/250)</gadget>
<output>1/1_000 = around 0.001</output>

<gadget id="calculator">8 / (1/1_000)</gadget>
<output>8_000</output>

<gadget id="calculator">8_000 / 250</gadget>
<output>32</output>

<result>32</result>