There are 208 children's books in the library, the number of adult books is 4 times the number of children's books, how many more adult books than children's books.
图书馆中有儿童图书208本，成人图书的本数是儿童图书本数的4倍，成人图书比儿童图书多多少本．
<gadget id="calculator">208 * 4</gadget>
<output>832</output>

<gadget id="calculator">832 - 208</gadget>
<output>624</output>

<result>624</result>