Zhang Hua took 200 yuan to buy books. After buying 7 books, there was 60 yuan left. How much is each book?
张华带200元去买书，买7本书后还剩下60元，每本书多少元？
<gadget id="calculator">200 - 60</gadget>
<output>140</output>

<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<result>20</result>