Mr. Wang has 48 compositions to correct, and 12 have already been corrected. If 9 articles are corrected every hour, how many hours will it take to complete the correction.
王老师要批改48篇作文，已经批改了12篇．如果每小时批改9篇，还要多少小时能够批改完．
<gadget id="calculator">48 - 12</gadget>
<output>36</output>

<gadget id="calculator">36 / 9</gadget>
<output>4</output>

<result>4</result>