A watermelon, the elder brother ate (1/8), the younger brother ate (2/8). How much of this watermelon did the brothers eat together?
一个西瓜，哥哥吃了(1/8)，弟弟吃了(2/8)．兄弟俩一共吃了这个西瓜的几分之几？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/8) + (1/4)</gadget>
<output>3/8 = around 0.375</output>

<result>3/8 = around 0.375</result>