A piece of cake, Xiaohong ate (1/4), Xiaoming ate (2/4), how much of the cake did they eat? How much of it is left uneaten?
一块蛋糕，小红吃了(1/4)，小明吃了(2/4)，他俩一共吃了这块蛋糕的几分之几？还剩几分之几没有吃？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>