The road repair team repaired a road, repaired the full length (1/9) in the first ten days, repaired the full length (1/8) in the middle ten days, and repaired as much in the second ten days as in the middle ten days. What fraction of the full length is left unrepaired?
修路队修一条路，上旬修了全长的(1/9)，中旬修了全长的(1/8)，下旬修的和中旬修的同样多．还剩全长的几分之几没有修？
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/9) + (1/8) + (1/8)</gadget>
<output>13/36 = around 0.361111</output>

<gadget id="calculator">1 - (13/36)</gadget>
<output>23/36 = around 0.638889</output>

<result>23/36 = around 0.638889</result>