The number of science and technology books in the school library is (2/3) that of story books, and the number of story books accounts for (3/5) of the total number of books. There are 4,500 books in the library. How many science and technology books are there?
学校图书室科技书的本数是故事书的(2/3)，故事书的本数占图书总数的(3/5)，图书室共有图书4500，科技书有多少本？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4_500 * (3/5)</gadget>
<output>2_700</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">2_700 * (2/3)</gadget>
<output>1_800</output>

<result>1_800</result>