The number of boys in a class is 5/7 of the number of girls, how much more girls than boys?
某班男生人数是女生人数的(5/7)，女生人数比男生人数多多少．
<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>