(1/3): (1/20) = (16/9): X.
(1/3)：(1/20)=(16/9)：X．
<gadget id="calculator">16 / 9</gadget>
<output>16/9 = around 1.777778</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(16/9) * (1/20)</gadget>
<output>4/45 = around 0.088889</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(4/45) / (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>