A 360-page fairy tale book, Xiao Gang finished reading it in 20 days, and Xiao Fang finished it in 30 days. On average, how many pages does Xiaogang read more than Xiaofang every day?
一本360页的童话书，小刚用20天读完，小芳用30天读完．小刚平均每天比小芳多读多少页？
<gadget id="calculator">360 / 20</gadget>
<output>18</output>

<gadget id="calculator">360 / 30</gadget>
<output>12</output>

<gadget id="calculator">18 - 12</gadget>
<output>6</output>

<result>6</result>