The master worker repaired a section of road. Those who repaired this section of road in the morning (2/5) and this section of road (1/5) in the afternoon, how much of this road is left unrepaired?
工人师傅修一段路，上午修了这段路的(2/5)，下午修了这段路(1/5)，这条路还剩下几分之几没有修？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (2/5) - (1/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>