There are two piles of coal, A and B. If (2/7) is transported from pile B to pile A, the weight of the two piles of coal is equal. How much more coal is there in pile B than in pile A?
有甲、乙两堆煤，如果从乙堆中运出(2/7)到甲堆，则两堆煤重量相等，原来乙堆煤比甲堆煤多多少
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">(5/7) - (2/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">(4/7) / (3/7)</gadget>
<output>4/3 = around 1.333333</output>

<result>4/3 = around 1.333333</result>