The school library bought 25 packs of extra-curricular books, 4 books in each pack, and spent a total of 1,000 yuan. How much is each book?
学校图书馆新进了25包课外书，每包4本，共花了1000元，每本几元？
<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">1_000 / 100</gadget>
<output>10</output>

<result>10</result>