(2/7)+(1/5)+(1/4)=how much.
(2/7)+(1/5)+(1/4)=多少．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(2/7) + (1/5) + (1/4)</gadget>
<output>103/140 = around 0.735714</output>

<result>103/140 = around 0.735714</result>