Xiaoqiang reads a book, the ratio of the number of pages he has read to the number of unread pages is 1:8, he has read 25 pages, how many pages are he unread?
小强读一本书，已读的页数和未读的页数的比是1：8，他已经读了25页，未读的有多少页？
<gadget id="calculator">25 * 8</gadget>
<output>200</output>

<result>200</result>