80% of the total length of a highway has been built in a certain city, which is exactly 25.6 kilometers. How many kilometers are left unrepaired?
某市修建一条高速公路，已经修了全长的80%，正好是25.6千米．还剩多少千米没有修？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">25.6 / (4/5)</gadget>
<output>32</output>

<gadget id="calculator">32 - 25.6</gadget>
<output>6.4</output>

<result>6.4</result>