There are 320 literature books in the school library, and the number of natural science books (4/9) is equivalent to the number of literature books (5/8). How many natural science books are there in the school library?
学校图书室有文学类书320本，自然科学类书数量的(4/9)相当于文学类书数量的(5/8)．学校图书室有自然科学类书多少本？
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(5/8) / (4/9)</gadget>
<output>45/32 = around 1.40625</output>

<gadget id="calculator">320 * (45/32)</gadget>
<output>450</output>

<result>450</result>