The length of an iron wire is equal to its (2/5) plus (2/5) meters, what is the length of this iron wire in meters.
一根铁丝长度等于它的(2/5)加上(2/5)米，这根铁丝的长度是多少米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

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

<result>2/3 = around 0.666667</result>