barrel of oil uses 25%, exactly 2.5 kilograms, how many kilograms does this barrel of oil weigh?
一桶油用25%，正好用去2.5千克，这桶油重多少千克？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2.5 / (1/4)</gadget>
<output>10</output>

<result>10</result>