How much of the whole journey has been done from A to B, and there is still 25% of the whole journey left.
由甲地到乙地已行全程的多少，还剩全程的25%没行．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>