For a simple fraction, if the numerator is increased by 1, the value of the fraction is equal to 1; if the denominator is increased by 1, the value of the fraction is equal to (2/3). What is the original fraction?
一个最简分数，如果分子加1，分数值就等于1；如果分母加1，分数值就等于(2/3)，原分数是多少．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>