The road construction team builds a road, the full length (1/4) is repaired on the first day, and the full length (1/2) is repaired on the second day, what fraction is left unrepaired?
筑路队修一条公路，第一天修全长的(1/4)，第二天修全长的(1/2)，还剩几分之几没有修？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

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