(1/5) of 40 meters is exactly how much of 50 meters.
40米的(1/5)正好是50米的多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 50</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">40 * (1/250)</gadget>
<output>4/25 = around 0.16</output>

<result>4/25 = around 0.16</result>