There are two boxes of apples, the first box is (9/10) kg heavier than the second box, if (1/4) kg is taken from the first box and put into the second box, then the first box is heavier than the second box How many kilograms are there more apples?
有两箱苹果，第一箱比第二箱重(9/10)kg，如果从第一箱中拿出(1/4)kg放入第二箱，这时第一箱苹果比第二箱苹果还多多少kg？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(9/10) - (1/2)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>