(2/5) is less than its reciprocal.
(2/5)比它的倒数少多少．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

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

<gadget id="calculator">(5/2) - (2/5)</gadget>
<output>21/10 = around 2.1</output>

<gadget id="calculator">(21/10) / (5/2)</gadget>
<output>21/25 = around 0.84</output>

<result>21/25 = around 0.84</result>