If the ratio of the numbers A and B is 5:9, then how much more the number B is than the number A.
甲乙两数的比是5：9，那么乙数比甲数多多少．
<gadget id="calculator">9 - 5</gadget>
<output>4</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>