The factory shipped 40 tons of coal and used up 62.5% of the total. How many tons are left?
工厂运来40吨煤，用去总数的62.5%，还剩多少吨？
<gadget id="calculator">62.5 / 100</gadget>
<output>0.625</output>

<gadget id="calculator">1 - 0.625</gadget>
<output>0.375</output>

<gadget id="calculator">40 * 0.375</gadget>
<output>15</output>

<result>15</result>