There are two barrels of oil, A and B, and the oil in A barrel is (9/10) kilograms more than that in B. If (4/10) kilograms of oil is taken from barrel A and put into barrel B, how much oil is in that barrel now? How many kilograms more?
有甲乙两桶油，甲桶油比乙桶油多(9/10)千克．如果从甲桶取出(4/10)千克油放入乙桶，那么现在那桶油多？多多少千克？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(9/10) - (2/5) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>