Wang Hui ate (1/3) of a watermelon, and he ate less (1/6) of this watermelon than his father. How much of this watermelon did Dad eat? (column equation solution)
一个西瓜，王辉吃了(1/3)，比爸爸少吃这个西瓜的(1/6)．爸爸吃了这个西瓜的几分之几？(列方程解答)
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/3) + (1/6)</gadget>
<output>1/2 = around 0.5</output>

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