Calculation: ((1/7)-(1/8))*(7/8).
计算：((1/7)-(1/8))*(7/8)．
<gadget id="calculator">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">(1/7) - (1/8)</gadget>
<output>1/56 = around 0.017857</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">(1/56) * (7/8)</gadget>
<output>1/64 = around 0.015625</output>

<result>1/64 = around 0.015625</result>