There is a bucket of water, 2/9 of it is used the first time, the same amount is used the second time, and it is all used up in the third time. What percentage of this bucket of water was used for the third time?
有一桶水，第一次用去它的(2/9)，第二次用去的与第一次同样多，第三次全部用完．第三次用去这桶水的几分之几？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(2/9) + (2/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 - (4/9)</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>