Xiaodong's stamps are less than Xiaohong's (1/5), so how much more Xiaohong's stamps are than Xiaodong's.
小东的邮票张数比小红的少(1/5)，那么小红的邮票张数比小东的多多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>