A watermelon, obviously ate (1/8), mother ate (3/8), what fraction of this watermelon is left?
一个西瓜，明明吃了(1/8)，妈妈吃了(3/8)，还剩下这个西瓜的几分之几？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (1/8) - (3/8)</gadget>
<output>1/2 = around 0.5</output>

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