There are 12 rows of pagoda trees in the mountain forest farm, with a total of 288 trees, and 18 rows of fir trees, with a total of 540 trees. How many more fir trees per row than pagoda trees per row?
山边林场栽了12行槐树，共有288棵，栽了18行杉树，共有540棵，平均每行杉树比每行槐树多多少棵？
<gadget id="calculator">540 / 18</gadget>
<output>30</output>

<gadget id="calculator">288 / 12</gadget>
<output>24</output>

<gadget id="calculator">30 - 24</gadget>
<output>6</output>

<result>6</result>