For a pile of sand, 6 tons more of the total (1/3) is transported in the first time, and less (1/3) is transported in the second time than the first time, and (1/9) of the sand is still left. How many tons is this pile of sand?
一堆沙子，第一次运走总数的(1/3)多6吨，第二次比第一次少运(1/3)，这时还剩下这堆沙子的(1/9)．这堆沙子共有多少吨？
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 - (1/3) - (2/9) - (1/9)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">10 / (1/3)</gadget>
<output>30</output>

<result>30</result>