There are 400 literature and art books in the school library, which is 252 less than twice the number of science and technology books. How many science and technology books are there in total?
学校图书室有文艺书400本，比科技书的2倍少252本，科技书共多少本？
<gadget id="calculator">400 + 252</gadget>
<output>652</output>

<gadget id="calculator">652 / 2</gadget>
<output>326</output>

<result>326</result>