The sum of (2/3) and (1/2) of a number is 420, what is this number?
一个数的(2/3)与它的(1/2)的和是420，这个数是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/3) + (1/2)</gadget>
<output>7/6 = around 1.166667</output>

<gadget id="calculator">420 / (7/6)</gadget>
<output>360</output>

<result>360</result>