A's number is 50, B's number is 70, how many percent is B's number greater than A's number?
甲数是50，乙数是70，乙数比甲数多百分之几？
<gadget id="calculator">70 - 50</gadget>
<output>20</output>

<gadget id="calculator">20 / 50</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>