There are 600 story books in the school library, and there are more story books than art books (1/5). How many literary books are there? (solution by equation)
学校图书室有故事书600本，故事书比文艺书多(1/5)．文艺书有几本？(用方程解)
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">600 / (6/5)</gadget>
<output>500</output>

<result>500</result>