The ratio of number A to number B is 5:4, how much less number B is than number A
甲数与乙数的比是5：4，乙数比甲数少多少
<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>