Calculation: ((1/4)+(1/5)+(1/6))*((1/5)+(1/6)+(1/7))-((1/4)+( 1/5)+(1/6)+(1/7))*((1/5)+(1/6)).
计算：((1/4)+(1/5)+(1/6))*((1/5)+(1/6)+(1/7))-((1/4)+(1/5)+(1/6)+(1/7))*((1/5)+(1/6))．
<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 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/4) + (1/5) + (1/6)</gadget>
<output>37/60 = around 0.616667</output>

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

<gadget id="calculator">(1/5) + (1/6) + (1/7)</gadget>
<output>107/210 = around 0.509524</output>

<gadget id="calculator">(37/60) * (107/210)</gadget>
<output>3_959/12_600 = around 0.314206</output>

<gadget id="calculator">(1/4) + (1/5) + (1/6) + (1/7)</gadget>
<output>319/420 = around 0.759524</output>

<gadget id="calculator">(1/5) + (1/6)</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">(319/420) * (11/30)</gadget>
<output>3_509/12_600 = around 0.278492</output>

<gadget id="calculator">(3_959/12_600) - (3_509/12_600)</gadget>
<output>1/28 = around 0.035714</output>

<result>1/28 = around 0.035714</result>