The school bought 9 boxes of popular science books, 80 books in each box, and the number of children's books bought is twice that of popular science books. How many children's books are there?
学校买来9箱科普书籍，每箱80本，买来的儿童读物的本数是科普书的2倍，儿童读物有多少本？
<gadget id="calculator">80 * 9 * 2</gadget>
<output>1_440</output>

<result>1_440</result>