There are 800 science and technology books, which are story books (4/7). How many story books are there?
科技书800本，是故事书的(4/7)．故事书多少本？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">800 / (4/7)</gadget>
<output>1_400</output>

<result>1_400</result>