There are 2400 storybooks in the school library, 529 are lent out in the morning and 240 in the afternoon, how many storybooks are left in the library?
学校图书馆有2400本故事书，上午借出529本，下午借出240本，图书馆还剩多少本故事书．
<gadget id="calculator">2_400 - 529 - 240</gadget>
<output>1_631</output>

<result>1_631</result>