The number of A is 1.25 times of the number of B, how much less than the number of B
甲数是乙数的1.25倍，乙数比甲数少多少
<gadget id="calculator">1.25 - 1</gadget>
<output>0.25</output>

<gadget id="calculator">0.25 / 1.25</gadget>
<output>0.2</output>

<result>0.2</result>