Cut open a watermelon, mother ate (1/3) of this watermelon, father ate (1/3) of this watermelon, and Xiao Ming ate the rest, how much of this watermelon Xiao Ming ate.
切开一个西瓜，妈妈吃了这个西瓜的(1/3)，爸爸吃了这个西瓜的(1/3)，剩下的小明吃了，小明吃了这个西瓜的多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3) - (1/3)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>