There are 2,340 damaged books in the school library. Students from four classes in the fifth grade come to repair them. There are 45 students in each class. On average, each person repairs 8 books. How many books are left unrepaired?
学校图书馆有2340本破损图书，五年级四个班的同学来修补，每班45人，平均每人修补8本，还差多少本没有修补？
<gadget id="calculator">45 * 4 * 8</gadget>
<output>1_440</output>

<gadget id="calculator">2_340 - 1_440</gadget>
<output>900</output>

<result>900</result>