A watermelon, Xiao Ming ate all (1/4), and Xiao Hua ate all (2/5), how much of this watermelon did they eat?
一个西瓜，小明吃了全部的(1/4)，小华吃了全部的(2/5)，他们一共吃了这个西瓜的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/4) + (2/5)</gadget>
<output>13/20 = around 0.65</output>

<result>13/20 = around 0.65</result>