Master Zhang processed a batch of parts. The original plan was to process 80 parts per day, and the processing was completed in 5 days. In fact, Master Zhang finished processing in only 4 days. How many more parts were processed per day than the original plan.
张师傅加工一批零件，原计划每天加工80个，5天加工完，实际张师傅只用4天就加工完了，实际每天比原计划多加工零件多少个．
<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">80 * (5/4)</gadget>
<output>100</output>

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

<result>20</result>