A pack of biscuits, Xiaodong ate (2/7), Xiaohong ate (3/7), how much did they eat in total?
一包饼干，小东吃了(2/7)，小红吃了(3/7)，一共吃了多少．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(2/7) + (3/7)</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>