The number of girls in a class is 4/5 of the number of boys, how much fewer girls than boys
某班女生人数是男生人数的(4/5)，女生人数比男生人数少多少
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>