Mom bought a watermelon, Dad and Xiaoli each ate (2/5), and the rest Mom ate, how much did Mom eat?
妈妈买回一个西瓜，爸爸和小丽各吃(2/5)，剩下的妈妈吃，妈妈吃了几分之几？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>