A bag of melon seeds weighs (5/2) kilograms, and if (2/5) is sold, how many kilograms are left?
一袋瓜子重(5/2)千克，卖掉了(2/5)，还剩多少千克．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

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

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(5/2) * (3/5)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>