barrel of oil weighs 100 kilograms. After 20% is used up, another 16% is poured in. How many kilograms of oil is left in the barrel?
一桶油重100千克，用掉20%后，又倒入16%，这桶油还有多少千克．
<gadget id="calculator">20 / 100</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">16 / 100</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">1 + (4/25)</gadget>
<output>29/25 = around 1.16</output>

<gadget id="calculator">100 * (4/5) * (29/25)</gadget>
<output>464/5 = around 92.8</output>

<result>464/5 = around 92.8</result>