(3/5) of 50 is equivalent to ((())/(())) of 80.
50的(3/5)相当于80的((())/(()))．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) / 80</gadget>
<output>3/400 = around 0.0075</output>

<gadget id="calculator">50 * (3/400)</gadget>
<output>3/8 = around 0.375</output>

<result>3/8 = around 0.375</result>