pile of coal has transported 24 tons, which is exactly 30% of the total tonnage. How many tons are left?
一堆煤运走了24吨，刚好是总吨数的30%，还剩多少吨？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">24 / (3/10)</gadget>
<output>80</output>

<gadget id="calculator">80 - 24</gadget>
<output>56</output>

<result>56</result>