piece of cake is divided into 8 pieces on average. Mom and Dad each ate 3 pieces, and Xiaoying ate 1 piece. What percentage of the cake did Dad and Xiaoying eat together?
一块蛋糕平均分成8块，爸爸妈妈各吃了3块，小瑛吃了1块，爸爸和小瑛一共吃了这块蛋糕的几分之几？
<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">(3/8) + (1/8)</gadget>
<output>1/2 = around 0.5</output>

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