The school library bought 1,000 new books and lent them to 12 classes. Each class borrowed 80 books. How many books are left?
学校图书馆新买来图书1000本，借给12个班，每班借80本，还剩下多少本？
<gadget id="calculator">12 * 80</gadget>
<output>960</output>

<gadget id="calculator">1_000 - 960</gadget>
<output>40</output>

<result>40</result>