Master Wang produces 640 parts in 8 hours, and Master Li produces 92 parts per hour. How many fewer parts does Master Wang produce per hour than Master Li?
王师傅8小时生产640个零件，李师傅每小时生产92个零件．王师傅平均每小时比李师傅少生产零件多少个？
<gadget id="calculator">640 / 8</gadget>
<output>80</output>

<gadget id="calculator">92 - 80</gadget>
<output>12</output>

<result>12</result>