After a pile of sand is transported away (5/7), what percentage of the pile of sand is left behind?
一堆沙子运走(5/7)后，还剩的比运走的少占这堆沙子的几分之几？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

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

<result>3/7 = around 0.428571</result>