A factory used 5,400 tons of water in April, saving 20% compared to March. How many tons of water was used in March?
某工厂四月份用水5400吨，比三月份节约20%，三月份用水多少吨？
<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">5_400 / (4/5)</gadget>
<output>6_750</output>

<result>6_750</result>