Hunan Provincial Science and Technology Museum has 300 visitors in the morning and 450 visitors in the afternoon. If every 50 tourists need a cleaner, how many more cleaners should be sent in the afternoon than in the morning?
湖南省科技馆星期一上午有游客300位，下午有游客450位．如果每50位游客需要一名保洁员，下午要比上午多派几名保洁员？
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<result>3</result>