0/2(18/39)=how much.
0/2(18/39)=多少．
<gadget id="calculator">18 / 39</gadget>
<output>6/13 = around 0.461538</output>

<gadget id="calculator">2 * (6/13)</gadget>
<output>12/13 = around 0.923077</output>

<gadget id="calculator">0 / (12/13)</gadget>
<output>0</output>

<result>0</result>