Xiaogang’s family used 12 tons of water in May, saving (1/7) compared to April. How many tons of water was used in April?
小刚家五月份用水12吨，比四月份节约了(1/7)，四月份用水多少吨．
<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">12 / (6/7)</gadget>
<output>14</output>

<result>14</result>