A bottle of fruit juice, if you drink (2/5) of it first, and then drink a fraction, you can finish the bottle of fruit juice?
一瓶果汁，先喝了它的(2/5)，再喝几分之几，就能喝完这瓶果汁？
<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>