After adopting water-saving measures, Mingming’s family used 10 tons of water in May, which is 20% less than in April. How many tons did Mingming’s family use in April?
采取节水措施后，明明家五月份用水10吨，比四月份节约了20%，明明家四月份用水多少吨？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">10 / (4/5)</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>