One moon cake was divided into 5 pieces on average, father and mother each ate one piece, and Xiao Ming ate the rest. How much of this mooncake did Xiao Ming eat?
一个月饼平均分成5块，爸爸和妈妈每人吃了一块，剩下的小明吃了．小明吃了这个月饼的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5) - (1/5)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>