For a book, Xiaoyu read (2/3) of the whole book on the first day and (1/9) of the whole book on the second day, how much of the whole book is left.
一本书，小雨第一天看了全书的(2/3)，第二天看了全书的(1/9)，还剩全书的多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">1 - (2/3) - (1/9)</gadget>
<output>2/9 = around 0.222222</output>

<result>2/9 = around 0.222222</result>