If 6:x=(1/4):9, then x=how much.
如果6：x=(1/4)：9，那么x=多少．
<gadget id="calculator">6 * 9</gadget>
<output>54</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">54 / (1/4)</gadget>
<output>216</output>

<result>216</result>