To build a (4/5) kilometer canal, the full length (1/3) was built on the first day, and the full length (1/4) was built on the second day. What fraction of the full length is left unfinished?
要修一条(4/5)千米的水渠，第一天修了全长的(1/3)，第二天修了全长(1/4)．还剩全长的几分之几没修？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/3) - (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>