There are 630 boys in a certain school, and the ratio of boys to girls is 7:8. How many girls are there in this school?
某校有男生630人，男、女生人数的比是7：8，这个学校女生有多少人？
<gadget id="calculator">8 / 7</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">630 * (8/7)</gadget>
<output>720</output>

<result>720</result>