Teachers and students of Experimental Primary School donated 1,200 books to "Hope Primary School", of which literary books accounted for (2/5), comic books accounted for 25%, and the rest were popular science books. How many copies of popular science books should be donated?
实验小学师生向"希望小学"捐赠图书1200册，其中文艺书占(2/5)，连环画占25%，其余都是科普读物．捐赠科普读物多少册？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (2/5) - (1/4)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1_200 * (7/20)</gadget>
<output>420</output>

<result>420</result>