There are 1,800 story books in the school library, which is 80 more than 50% of the literary books. How many literary books are there in the school?
学校图书室有故事书1800本，比文艺书的50%还多80本，学校共有文艺书多少本？
<gadget id="calculator">1_800 - 80</gadget>
<output>1_720</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1_720 / (1/2)</gadget>
<output>3_440</output>

<result>3_440</result>