A piece of cake, Dongdong ate (2/8), Xiaoyu ate (1/8), how much is left
一块蛋糕，东东吃了(2/8)，小宇吃了(1/8)，还剩多少
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/4) - (1/8)</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>