barrel of oil weighs 50 kg, how many tons does 20 barrels weigh?
一桶油重50千克，20桶重多少吨．
<gadget id="calculator">50 * 20</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 / 1_000</gadget>
<output>1</output>

<result>1</result>