Calculation: ((1/2)+(1/4)+(1/6)+(1/8))-((1/3)+(1/6)+(1/9)+(1/ 12))+((1/4)+(1/8)+(1/12)+(1/16))-((1/5)+(1/10)+(1/15)+( 1/20)) = how much.
计算：((1/2)+(1/4)+(1/6)+(1/8))-((1/3)+(1/6)+(1/9)+(1/12))+((1/4)+(1/8)+(1/12)+(1/16))-((1/5)+(1/10)+(1/15)+(1/20))=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">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/2) + (1/3) + (1/4)</gadget>
<output>25/12 = around 2.083333</output>

<gadget id="calculator">(1/2) * (25/12)</gadget>
<output>25/24 = around 1.041667</output>

<gadget id="calculator">(1/3) * (25/12)</gadget>
<output>25/36 = around 0.694444</output>

<gadget id="calculator">(25/24) - (25/36)</gadget>
<output>25/72 = around 0.347222</output>

<gadget id="calculator">(1/4) * (25/12)</gadget>
<output>25/48 = around 0.520833</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * (25/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(25/48) - (5/12)</gadget>
<output>5/48 = around 0.104167</output>

<gadget id="calculator">(25/72) + (5/48)</gadget>
<output>65/144 = around 0.451389</output>

<result>65/144 = around 0.451389</result>