There are two bookshelves, A and B. It is known that there are 1200 books in the A bookshelf, 200 more than (1/2) the B bookshelf. How many books are there in the B bookshelf?
甲、乙两个书架，已知甲书架有书1200本，比乙书架的(1/2)多200本，乙书架有书多少本？
<gadget id="calculator">1_200 - 200</gadget>
<output>1_000</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1_000 / (1/2)</gadget>
<output>2_000</output>

<result>2_000</result>