Master Liu processed 180 parts from 9:00 am to 3:00 pm. How many parts are processed on average per hour?
刘师傅从上午9时到下午3时一共加工了180个零件，平均每小时加工多少个？
<gadget id="calculator">15 - 9</gadget>
<output>6</output>

<gadget id="calculator">180 / 6</gadget>
<output>30</output>

<result>30</result>