Calculation: 1-(1/2)*{1-(1/3)(1-(1/4)*(1-(1/5)))}=how much.
计算：1-(1/2)*{1-(1/3)(1-(1/4)*(1-(1/5)))}=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/3) * (4/5)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 - (4/15)</gadget>
<output>11/15 = around 0.733333</output>

<gadget id="calculator">(1/2) * (11/15)</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">1 - (11/30)</gadget>
<output>19/30 = around 0.633333</output>

<result>19/30 = around 0.633333</result>