If the ratio of the two numbers of A and B is 4:5, then how much more B is than A.
如果甲乙两个数的比是4：5，那么乙比甲多多少．
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>