(1-0.45/(9/10))*(4/15).
(1-0.45/(9/10))*(4/15)．
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">0.45 / (9/10)</gadget>
<output>0.5</output>

<gadget id="calculator">1 - 0.5</gadget>
<output>0.5</output>

<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">0.5 * (4/15)</gadget>
<output>0.133333</output>

<result>0.133333</result>