Master Li needs to process 55 parts, and has already processed 15 parts. If 8 pieces are processed per hour, how many hours will it take to finish processing.
李师傅要加工55个零件，已经加工了15个．如果每小时加工8个，还要多少小时能够加工完．
<gadget id="calculator">55 - 15</gadget>
<output>40</output>

<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<result>5</result>