The staff canteen planned to burn 5 tons of coal in April, but actually burned 4.8 tons of coal. What percentage did you save?
职工食堂4月份计划烧煤5吨，实际烧煤4.8吨．节约了百分之几？
<gadget id="calculator">5 - 4.8</gadget>
<output>0.2</output>

<gadget id="calculator">0.2 / 5</gadget>
<output>0.04</output>

<result>0.04</result>