The number of girls is the number of boys (4/5), the number of boys is the number of girls
女生是男生人数的(4/5)，男生是女生人数的多少
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / (4/5) / 1</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>