The school library purchased a batch of books and shipped back 120 bundles of 50 books, and there are still 2,000 books that have not been shipped back. How many books are there in this batch?
学校图书室购买了一批书，运回了120捆，每捆50本，还有2000本没有运回，这批书有多少本？
<gadget id="calculator">120 * 50</gadget>
<output>6_000</output>

<gadget id="calculator">6_000 + 2_000</gadget>
<output>8_000</output>

<result>8_000</result>