A piece of cake, mother ate 1/3 of it, father ate 1/2 of it, and Xiao Ming ate the rest, how much of this cake did Xiao Ming eat.
一块蛋糕，妈妈吃了它的1/3，爸爸吃了它的1/2，剩下的小明全吃了，小明吃了这块蛋糕的多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/3) - (1/2)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>