Mother bought a piece of cake, father and mother ate (1/4) of this cake respectively, and obviously ate the rest, how much did they eat?
妈妈买来一块蛋糕，爸爸和妈妈分别吃了这块蛋糕的(1/4)，剩下的明明吃，明明吃了几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4) - (1/4)</gadget>
<output>1/2 = around 0.5</output>

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