A train travels for 14 hours on the first day, covering a total of 882 kilometers; on the second day, it takes 18 hours and travels a total of 972 kilometers. On the second day, how many kilometers per hour did you travel less on average than on the first day?
一列火车第一天行14小时，共行882千米；第二天了18小时，共行972千米．第二天比第一天平均每小时少行多少千米？
<gadget id="calculator">882 / 14</gadget>
<output>63</output>

<gadget id="calculator">972 / 18</gadget>
<output>54</output>

<gadget id="calculator">63 - 54</gadget>
<output>9</output>

<result>9</result>