number is 500 after adding its (2/3), what is this number? (solution by equation)
一个数增加它的(2/3)后是500，这个数是多少？(用方程解)
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 + (2/3)</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">500 / (5/3)</gadget>
<output>300</output>

<result>300</result>