To build a canal (7/8) meters long, the engineering team repaired the full length (1/4) in the first week, and after the second week, half of the full length remained unrepaired. What fraction of the full length was repaired in the second week?
修一条水渠长(7/8)米，工程队第一周修了全长的(1/4)，第二周修了后，还剩下全长的一半没有修．第二周修了全长的几分之几？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">1 - (1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>