There are 2,800 storybooks in the school library. After lent out to 10 classes on average, there are 400 books left. How many storybooks are borrowed by each class on average?
学校图书室里有2800本故事书，平均借给10个班后，还剩400本，平均每班借了多少本故事书？
<gadget id="calculator">2_800 - 400</gadget>
<output>2_400</output>

<gadget id="calculator">2_400 / 10</gadget>
<output>240</output>

<result>240</result>