There are 2 kilograms of oil in a barrel, (1/5) of the oil is poured out for the first time, and (1/5) is poured out for the second time, how many kilograms of oil are left in the barrel.
一桶油2千克，第一次倒出油的(1/5)，第二次倒出(1/5)千克，桶内还剩油多少千克．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">2 - (2/5) - (1/5)</gadget>
<output>7/5 = around 1.4</output>

<result>7/5 = around 1.4</result>