To build a section of road, the whole road (2/9) was repaired on the first day, and the whole road (1/9) was repaired on the second day, what fraction of the whole road is left unrepaired?
修一段公路，第一天修了全程的(2/9)，第二天修了全程的(1/9)，还剩下全程的几分之几没修？
<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 - (2/9) - (1/9)</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>