A box of fruit has A kilograms, sell (2/5), how many kilograms are left.
一箱水果有A千克，卖去(2/5)，还剩下多少千克．
<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>

<result>3/5 = around 0.6</result>