have 40 yuan, and I spent 32 yuan to buy a schoolbag. I bought 2 more books with the remaining money. How much did I spend on each book?
我有40元钱，买一个书包用了32元，剩下的钱又买了2本书，每本书用了多少元？
<gadget id="calculator">40 - 32</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<result>4</result>