Xiao Min reads a book, the first day read this book (2/9), the second day more than the first day read this book (1/9). How much of this book is still missing?
小敏看一本书，第一天看了这本书的(2/9)，第二天比第一天多看了这本书的(1/9)．这本书还有几分之几没看？
<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">(2/9) + (1/9)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (2/9) - (1/3)</gadget>
<output>4/9 = around 0.444444</output>

<result>4/9 = around 0.444444</result>