A cake, I ate (3/8), Dad ate (1/8). What fraction is left?
一个蛋糕，我吃了(3/8)，爸爸吃了(1/8)．还剩下几分之几？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

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

<gadget id="calculator">1 - (3/8) - (1/8)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>