Factory workers process a batch of parts. If they make 50 parts every day, they will finish 8 days later than the original plan; if they make 60 parts the next day, they can finish it 5 days earlier.
工厂工人加工一批零件，如果每天做50个，要比原计划晚8天完成；如果第天做60个，就可以提前5天完成，那么，这批零件共有多少个．
<gadget id="calculator">50 * 8</gadget>
<output>400</output>

<gadget id="calculator">60 * 5</gadget>
<output>300</output>

<gadget id="calculator">400 + 300</gadget>
<output>700</output>

<gadget id="calculator">60 - 50</gadget>
<output>10</output>

<gadget id="calculator">700 / 10</gadget>
<output>70</output>

<gadget id="calculator">70 - 5</gadget>
<output>65</output>

<gadget id="calculator">60 * 65</gadget>
<output>3_900</output>

<result>3_900</result>