The school library bought 1,000 new books and lent them to 12 classes. Each class borrowed 75 books. How many books are left?
学校图书馆新买来图书1,000本，借给12个班，每班借75本，还剩下多少本？
<gadget id="calculator">75 * 12</gadget>
<output>900</output>

<gadget id="calculator">1_000 - 900</gadget>
<output>100</output>

<result>100</result>