Processing a batch of parts, the original plan was to process 80 pieces per day, and the task was completed on schedule. Due to the improvement of production technology, 100 pieces are actually processed every day. In this way, not only the processing task is completed 4 days ahead of schedule, but also 100 more pieces are processed. How many parts do they actually process.
加工一批零件，原计划每天加工80个，正好如期完成任务．由于改进了生产技术，实际每天加工100个，这样，不仅提前4天完成加工任务，而且还多加工了100个．他们实际加工零件多少个．
<gadget id="calculator">100 * 4</gadget>
<output>400</output>

<gadget id="calculator">400 + 100</gadget>
<output>500</output>

<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">500 / 20</gadget>
<output>25</output>

<gadget id="calculator">25 * 80</gadget>
<output>2_000</output>

<result>2_000</result>