The school library bought a total of 1,600 volumes of three kinds of books, including 235 science and technology books, 220 more story books than science and technology books, and the rest are teaching reference books. How many teaching reference books are there?
学校图书馆买来三种图书共计1600册，其中科技书235册，故事书比科技书多220册，其余的全部是教学参考书，教学参考书多少册？
<gadget id="calculator">235 + 200</gadget>
<output>435</output>

<gadget id="calculator">1_600 - 235 - 435</gadget>
<output>930</output>

<result>930</result>