The electricity consumption in September is (1/7) less than that in August, and the electricity consumption in August is ((())/(())) in September.
九月份用电比八月份节约(1/7)，八月份用电量是九月份的((())/(()))．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">1 / (6/7)</gadget>
<output>7/6 = around 1.166667</output>

<result>7/6 = around 1.166667</result>