There are 400 science books in the library, more than story books (3/5). How many story books are there?
图书馆有科技书400本，比故事书多(3/5)，故事书有多少本？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + (3/5)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">400 / (8/5)</gadget>
<output>250</output>

<result>250</result>