27: Χ=15: (5/9).
27：Χ=15：(5/9)．
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">27 * (5/9)</gadget>
<output>15</output>

<gadget id="calculator">15 / 15</gadget>
<output>1</output>

<result>1</result>