The ratio of number A to number B is 3:8, so how much less number A is than number B.
甲数与乙数的比是3：8，那么甲数比乙数少多少．
<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>