If (2/5) kg is taken from bag A and put into bag B. The weights of the two bags are exactly equal. How much does bag A weigh more than bag B?
如果从甲袋中取出(2/5)千克放入乙袋中．两袋的重量刚好相等．原来甲袋比乙袋重多少千克？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) + (2/5)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>