A batch of cement is 2 tons, and (2/5) of the total amount was transported for the first time, and the same amount was transported for the second time as the first time, what fraction of the total amount remained?
一批水泥2吨，第一次运走了总数的(2/5)，第二次运的和第一次同样多，还剩总数几分之几没有运走？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) + (2/5)</gadget>
<output>4/5 = around 0.8</output>

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

<result>1/5 = around 0.2</result>