A book has 400 pages, Xiaohong has already read 265 pages, and plans to finish the rest in 9 days, how many good pages do she need to read on average every day?
一本书有400页，小红已经看了265页，余下的准备9天看完，平均每天要看多少个好页？
<gadget id="calculator">400 - 265</gadget>
<output>135</output>

<gadget id="calculator">135 / 9</gadget>
<output>15</output>

<result>15</result>