A piece of cake, Xiao Hua ate (3/5) of it, how much is left?
一块蛋糕，小华吃了它的(3/5)，还剩下几分之几？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

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