The ratio of boys to girls is 5:4, so how much less girls than boys
男生与女生的人数的比是5：4，那么女生比男生少多少
<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>