There are more boys than girls in a certain class (2/7), how much less girls than boys in this class.
某班男生比女生多(2/7)，这个班女生比男生少多少．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 + (2/7)</gadget>
<output>9/7 = around 1.285714</output>

<gadget id="calculator">(2/7) / (9/7)</gadget>
<output>2/9 = around 0.222222</output>

<result>2/9 = around 0.222222</result>