1/((2/5)*how much-(1/5))=(5/3).
1/((2/5)*多少-(1/5))=(5/3)．
<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(5/3) * (1/5)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

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

<gadget id="calculator">(5/3) * (2/5)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(4/3) / (2/3)</gadget>
<output>2</output>

<result>2</result>