Mom bought a cake and divided it into 8 pieces on average. Xiao Ming ate 1 piece, and mother ate 2 pieces. Dad ate the same amount as mother ate. What fraction of the cake is left?
妈妈买了一个蛋糕，平均分成8块，小明吃了1块，妈妈吃了两块，爸爸吃的和妈妈吃的同样多，还剩这个蛋糕的几分之几？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

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

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