A park has 180 visitors in the morning and 270 in the afternoon. If every 30 tourists need a cleaner, how many more cleaners should be sent in the afternoon than in the morning?
某公园上午有游人180人，下午有270人．如果每30位游人需要一名保洁员，下午要比上午多派几名保洁员？
<gadget id="calculator">270 / 30</gadget>
<output>9</output>

<gadget id="calculator">180 / 30</gadget>
<output>6</output>

<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<result>3</result>