To build a canal, (1/3) has been built, and there are 18 kilometers left. How long is this canal?
修一条水渠，已经修了(1/3)，剩下18千米，这条水渠有多长？
<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">18 / (2/3)</gadget>
<output>27</output>

<result>27</result>