Calculation: ((1/2)-(1/3))+((1/4)-(1/5))+((1/7)-(1/10))+((1/14) -(1/15))+((1/28)+(1/30)).
计算：((1/2)-(1/3))+((1/4)-(1/5))+((1/7)-(1/10))+((1/14)-(1/15))+((1/28)+(1/30))．
<gadget id="calculator">14 / 28</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">10 / 30</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/2) - (1/3)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">7 / 28</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">6 / 30</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">4 / 28</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">3 / 30</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/7) - (1/10)</gadget>
<output>3/70 = around 0.042857</output>

<gadget id="calculator">2 / 28</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">2 / 30</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/14) - (1/15)</gadget>
<output>1/210 = around 0.004762</output>

<gadget id="calculator">1 / 28</gadget>
<output>1/28 = around 0.035714</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/28) - (1/30)</gadget>
<output>1/420 = around 0.002381</output>

<gadget id="calculator">(1/6) + (1/20) + (3/70) + (1/210) + (1/420)</gadget>
<output>4/15 = around 0.266667</output>

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