The school newly bought 1320 books, distributed 485 books to the fourth grade, 515 books to the third grade, and distributed the rest to the second grade. How many books are given to the second grade.
学校新买来图书1320本，分给四年级485本，三年级515本，其余的分给二年级．分给二年级多少本．
<gadget id="calculator">485 + 515</gadget>
<output>1_000</output>

<gadget id="calculator">1_320 - 1_000</gadget>
<output>320</output>

<result>320</result>