After transferring (1/5) the coal from pile A to pile B, the two piles have the same amount of coal, how much less pile B is than pile A
将甲堆煤调出(1/5)到乙堆后，两堆煤一样多，原来乙堆比甲堆少多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 2</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>