There are 800 new books added to the school library, among which the number of comic books accounts for (1/5) of the total number of new additions, story books account for (1/4) of the total number of new additions, and the rest are popular science books. How many popular science books are there?
学校图书室新添800本图书，其中连环画的本数占新添总数的(1/5)，故事书占新添总数的(1/4)，其余是科普读物，科普读物有多少本？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 - (1/5) - (1/4)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">800 * (11/20)</gadget>
<output>440</output>

<result>440</result>