If (1/3) of the total length of a piece of wood is used up, there is still (1/3) meter left. How many meters is the original length of this piece of wood?
一根木材用去全长的(1/3)，还剩下(1/3)米，这根木材原来长多少米．
<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">(1/3) / (2/3)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>