(5/6): 0.9=(2/3): x.
(5/6)：0.9=(2/3)：x．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * 0.9</gadget>
<output>0.6</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">0.6 * (6/5)</gadget>
<output>0.72</output>

<result>0.72</result>