A piece of paper Xiaoxiao origami crane is used up (2/9), the naughty origami crane is used up (3/9), how much is left.
一张纸笑笑折纸鹤用去了(2/9)，淘气折纸鹤用去了(3/9)，还剩多少．
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">3 / 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>