Xiao Ming divides a large pancake into 8 pieces on average, Xiao Ming eats 2 pieces, father eats 3 pieces, and gives the rest to his mother. What fraction of the big cake did Xiao Ming and his father eat together?
小明把一个大饼平均分成了8块，小明吃了2块，爸爸吃了3块，剩下的给妈妈吃，小明和爸爸共吃了这个大饼的几分之几？
<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">(1/4) + (3/8)</gadget>
<output>5/8 = around 0.625</output>

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