Liu Xiaojuan reads a world famous book, with an average of 27 pages per day. After reading it for 15 days, she finds that there are still 87 pages she has not read. How many pages does this world famous book have?
刘晓娟读一本世界名著，平均每天读27页，读了15天，发现还有87页没有读，这本世界名著共有多少页？
<gadget id="calculator">27 * 15</gadget>
<output>405</output>

<gadget id="calculator">405 + 87</gadget>
<output>492</output>

<result>492</result>