A section of the road was covered on the first day (1/5), and the rest (1/4) on the second day. How much of the entire distance was covered in two days?
一段路第一天行了全程的(1/5)，第二天行了余下的(1/4)，两天一共行了完全程的多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) * (1/4)</gadget>
<output>1/5 = around 0.2</output>

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

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