Boys belong to girls (5/8), then the number of girls is the total number ((())/(())).
男生是女生的(5/8)，那么女生人数是全部人数的((())/(()))．
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">8 * (5/8)</gadget>
<output>5</output>

<gadget id="calculator">8 + 5</gadget>
<output>13</output>

<gadget id="calculator">8 / 13</gadget>
<output>8/13 = around 0.615385</output>

<result>8/13 = around 0.615385</result>