Master Wang produces 492 parts in 6 hours, and Master Li produces 420 parts in 4 hours. How many fewer parts does Master Wang produce per hour than Master Li?
王师傅6小时生产492个零件，李师傅4小时生产420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">420 / 4</gadget>
<output>105</output>

<gadget id="calculator">492 / 6</gadget>
<output>82</output>

<gadget id="calculator">105 - 82</gadget>
<output>23</output>

<result>23</result>