If the ratio of A and B is 4:5, how much less is A than B?
若甲、乙两数之比是4：5，则甲数比乙数少多少
<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>