Xiaopang cut a birthday cake into 8 pieces on average, father ate 2 pieces, mother ate 3 pieces, and Xiaopang ate the rest by himself. How much cake did Xiaopang eat?
小胖把一个生日蛋糕平均切成8块，爸爸吃了2块，妈妈吃了3块，剩下的小胖自己吃，小胖吃了几分之几个蛋糕？
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (1/4) - (3/8)</gadget>
<output>3/8 = around 0.375</output>

<result>3/8 = around 0.375</result>