There are 400 literature and art books, literature and art books are science and technology books (4/5), story books are less than science and technology books (1/4). How many books are there in total?
文艺书400本，文艺书是科技书的(4/5)，故事书比科技书少(1/4)．三种书共有多少本？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">400 / (4/5)</gadget>
<output>500</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">500 * (3/4)</gadget>
<output>375</output>

<gadget id="calculator">400 + 500 + 375</gadget>
<output>1_275</output>

<result>1_275</result>