A book has two volumes, the first volume and the second volume, with a total of 960 pages. It is known that the number of pages in the first volume is (7/9) the number of pages in the second volume. How many pages are there in the first volume of this book?
一本书有上、下两册，共960页，已知上册的页数是下册页数的(7/9)，这本书上册有多少页？
<gadget id="calculator">7 + 9</gadget>
<output>16</output>

<gadget id="calculator">7 / 16</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">960 * (7/16)</gadget>
<output>420</output>

<result>420</result>