On average, Uncle Zhao processes 28 parts per working day. If calculated as 23 working days per month, how many parts can Uncle Zhao process per month?
赵叔叔平均每个工作日加工28个零件，如果每月按23个工作日计算，赵叔叔每月可以加工多少个零件？
<gadget id="calculator">28 * 23</gadget>
<output>644</output>

<result>644</result>