If (1/3) of a copper wire is subtracted, and there are 4 meters left, how long is the copper wire in meters?
一根铜丝减掉它的(1/3)，还剩4米，则这根铜丝长多少米．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">4 / (2/3)</gadget>
<output>6</output>

<result>6</result>