A barrel of oil weighs 90 kilograms, pour out (2/5) for the first time, and pour out (4/5) kilograms for the second time, how many kilograms are left?
一桶油重90千克，第一次倒出(2/5)，第二次倒出(4/5)千克，还剩多少千克？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">90 * (3/5)</gadget>
<output>54</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">54 - (4/5)</gadget>
<output>266/5 = around 53.2</output>

<result>266/5 = around 53.2</result>