factory used 560 tons of water in September, saving (1/8) compared to the original plan. How many tons of water was originally planned in September?
某工厂九月份用水560吨，比原计划节约了(1/8)．九月份原计划用水多少吨？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/8)</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">560 / (7/8)</gadget>
<output>640</output>

<result>640</result>