(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)=how much.
(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)=多少．
<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 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/4) - (1/5)</gadget>
<output>-1/5 = around -0.2</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/6) - (1/6) - (1/7)</gadget>
<output>-1/7 = around -0.142857</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/8) - (1/8) - (1/9)</gadget>
<output>-1/9 = around -0.111111</output>

<gadget id="calculator">(1/3) + (-1/5) + (1/5) + (-1/7) + (1/7) + (-1/9)</gadget>
<output>2/9 = around 0.222222</output>

<result>2/9 = around 0.222222</result>