Master Zhang can process 6 parts per hour on average. According to this calculation, how many parts can he process in total from 8:20 am to 11:20 am?
张师傅平均每小时能加工6个零件，照这样计算，他上午8时20分到11时20分，一共可以加工多少个零件？
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>