There are 9 tons of coal in a pile, (1/3) is removed, and ((())/(())) is left, how many tons are left.
一堆煤有9吨，运走了(1/3)，还剩((())/(()))，还剩多少吨．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">9 * (2/3)</gadget>
<output>6</output>

<result>6</result>