There are 260 students in the sixth grade of a certain school, of which boys account for 8/13 of the total number of students in the whole grade. In order for girls to account for at least 3/7 of the total number, how many girls should be recruited at least?
某校六年级有学生260人，其中男生占全年级总数的(8/13)，为了让女生至少能占总人数的(3/7)，那么至少还要招多少名女生？
<gadget id="calculator">8 / 13</gadget>
<output>8/13 = around 0.615385</output>

<gadget id="calculator">260 * (8/13)</gadget>
<output>160</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">160 / (4/7)</gadget>
<output>280</output>

<gadget id="calculator">280 - 260</gadget>
<output>20</output>

<result>20</result>