Obviously reading a book, I read 160 pages in the first 4 days. At this speed, it will take 18 days to finish the book. How many pages does the book have?
明明看一本书，前4天看了160页，照这样的速度，还要18天才能看完这本书，这本书一共有多少页？
<gadget id="calculator">160 / 4</gadget>
<output>40</output>

<gadget id="calculator">18 + 4</gadget>
<output>22</output>

<gadget id="calculator">40 * 22</gadget>
<output>880</output>

<result>880</result>