Uncle Li processed 20 parts per hour on average, 60 in the morning and 100 in the afternoon. How many hours did Uncle Li work in total?
李叔叔平均每小时加工20个零件，上午加工了60个，下午加工了100个，李叔叔一共工作了几小时？
<gadget id="calculator">60 + 100</gadget>
<output>160</output>

<gadget id="calculator">160 / 20</gadget>
<output>8</output>

<result>8</result>