To build a road, the full length (2/9) was repaired in the first month, the full length (2/7) was repaired in the second month, and the same amount was repaired in the third month as in the first month, leaving the whole road What fraction of the length has not been repaired?
修一条路，第一个月修了全长的(2/9)，第二个月修了全长的(2/7)，第三个月修的和第一月的一样多，还剩下全长的几分之几没有修？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/9) + (2/7) + (2/9)</gadget>
<output>46/63 = around 0.730159</output>

<gadget id="calculator">1 - (46/63)</gadget>
<output>17/63 = around 0.269841</output>

<result>17/63 = around 0.269841</result>