The ratio of boys to girls is 5:4, how much less girls than boys
男生人数与女生的比是5：4，女生人数比男生人数少多少
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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