Divide a watermelon into 8 pieces on average, Xiaodong ate 3 pieces, Xiao Ming ate 2 pieces, Xiaohong ate 1 piece, what fraction of the watermelon did they eat in total? How much of this watermelon is left?
把一个西瓜平均分成了8块，小东吃了3块，小明吃了2块，小红吃了1块，他们一共吃了这个西瓜的几分之几？这个西瓜还剩下几分这几？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

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

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(3/8) + (1/4) + (1/8)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>