The oil in barrel A is 0.9 kg more than the oil in barrel B. Now take out 0.4 kg from barrel A and pour it into barrel B. At this time, barrel A has more oil than barrel B by how many kilograms.
甲桶的油比乙桶的油多0.9千克，现在从甲桶里取出0.4千克倒入乙桶，这时甲桶比乙桶的油还多多少千克．
<gadget id="calculator">0.9 - 0.4 - 0.4</gadget>
<output>0.1</output>

<result>0.1</result>