barrel of oil has a net weight of 80 kilograms, pour out (2/5), how many kilograms are left?
一桶油净重80千克，倒出(2/5)，还剩多少千克？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">80 * (2/5)</gadget>
<output>32</output>

<gadget id="calculator">80 - 32</gadget>
<output>48</output>

<result>48</result>