Xiao Ming reads a book and has already read 250 pages, and the remaining pages are 8 times as many as he has read. How many pages are there in this book?
小明读一本书，已经读了250页，余下的是已经读的8倍，这本书共多少页？
<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<gadget id="calculator">250 * 9</gadget>
<output>2_250</output>

<result>2_250</result>