Xiao Ming ate a piece of cake (2/5), how much is left?
小明吃了一块蛋糕的(2/5)，还剩多少没有吃？
<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>