The master and the apprentice process 200 parts each, and the master processes 25 parts per hour. When the task is completed, the apprentice has to process for 2 hours to complete the task. How many parts does the apprentice process per hour?
师傅和徒弟每人加工200个零件，师傅每小时加工25个，完成任务时，徒弟还要加工2小时才能完成任务，徒弟每小时加工多少个零件？
<gadget id="calculator">200 / 25</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">200 / 10</gadget>
<output>20</output>

<result>20</result>