(4/9)+(3/9)=how much.
(4/9)+(3/9)=多少．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">3 / 9</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(4/9) + (1/3)</gadget>
<output>7/9 = around 0.777778</output>

<result>7/9 = around 0.777778</result>