If the number A is increased by 25%, it will be equal to the number B, so what percentage of the original number A is the number B?
甲数如果增加25%就和乙数相等，那么原来甲数是乙数的百分之几？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">1 / (5/4)</gadget>
<output>4/5 = around 0.8</output>

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